Well folks I have seen a lot of these issues posted separate but I thought it would be nice to put this all in one post. Here is some of the lessons learned from my 1F to 2F swap. Mine was a 79 2f with complete drive train ---yours may vary a little
the point is while it is not that hard it is not a straight bolt in and you may want to know some details up front to help with your decisions ( read in my case ---blunders) to save time and money.
I got some good advice from the MUD experts who you always see posting up and helping out
1st piece of advice ---try to get everything whole and complete and preferably stock --not missing accessories like alt, fuel pumps, carbs, air cleaner, cables etc. These items add up$$$
will it affect the value?---Only the purest of the purists would object to a 2F 4 speed most folks seem to like this route or the SBC
I did it in my 71
A few words of advice (ok turned out to be many words)
SWAPPING OUT A 1F 3 SPEED FOR A 2 F FOUR SPEED
CLUTCH---You can choose to use your finger style clutch set up-older type but use everything together --bell housing, fork, fork pivot, throw out bearing etc or you can upgrade to the diaphragm newer style clutch
heres a post that shows them both and a rear main seal which you might as well do now as well:
https://forum.ih8mud.com/40-55-series-tech/245021-pics-oem-p-ns-rear-main-clutch-change.html
I got all OEM from CDAN with RMS for about $400, order an extra clip for the throw out bearing retainer--that little bugger runs away!
with the 4 speed the slave cylinder is on the rh side but the pivot, fork, and cylinder can be moved to the LH side sweet and easy or make new lines from your clutch MC to your slave cyl
EMER/PARK BRAKE---decide what you are going to do about the parking brake. The 4 spd is longer and you will probably not be able to get the drum off once the drivetrain is installed cause it is real close to the crossmember. Obtion B is to cut and turn the cross member. Or you can remove the rear motor mounts each time you service the parking brake. I personally dont consider LINELOCK as a viable option because it would not make a good emergency brake. I recently found out the MAF brake will not fit either----and it is not cheap, OUCH!
Also you will need a parking brake cable to suit both your park brake drum and the handle end---this is different for different years. I think the 76 model satisfied my prob but check with the supplier for advice on your year model . You may receive the drivetrain with the cables cut
The good news is the drum brake set up will probably not need servicing for a long time if ever if it is working but what if you break a cable?
FAN SHROUD --- 2F Fan may stick out further, a 1F pump would fit but you lose the oil cooler if you have one and you only get a metal 4 blade fan and probably only one pulley---you may need 2 for power steering. Another option is the water pump/pulley/fan combo. I got a 76 clutch fan with a 7 blade fan. I lengthened the rad mount holes on the chassis so I could slide it forward slightly. I widened the shroud a little too by cutting out the connecting strip of metal on the bottom and bolting in a new piece that is slightly longer. I am told the AUSSIE 8 blade fits fine without any mod but MAF was out of Stock, CCOt ALSO. You can buy a 2F shroud or some folks run with no shroud but I didnt want that.
SPEEDOMETER CABLE. I used the 1F one so it would go into my speedo housing the 2f one didnt
ALTERNATOR - I ordered all the RH mount stuff from SOR including bolts and a two pulley water pump pulley. I did this so I could do PS mod later. I ordered the adjuster bolt but I cant see how it works with the Inter Volt reg Alternator I got but the mount works fine. A 1F alt will not work unless you change the front face to the straight clocking instead of off set. I also ordered a external VR alternator by mistake and all that will take is re-routing the wires. But the internal VR mod is easy. I don't like seeing the batt cable straight to the alternator it is safer to use a fusible link here.
DESMOG? If you decide to DESMOG you get rid of a bunch of clutter. Some of the smog stuff may not be with your early model since it may be fender mounted. For Desmog Jim C and Mark A are the acknowledged experts and will PROBABLY need both the dizzy and carb to do it right--BUT ASK THEM. When you remove the air rail there are nice OEM allen plugs to take their place or you can get some square head brass plugs from ACE with slightly different threads but they screw right in and work. There are a couple good posts on DESMOG and I think an FAQ.
EXHAUST- if you go with headers you will lose the warm up feature of the OEM manifold which has a butterfly to route warm air up to the bottom of the intake manifold. This may cause long warm ups in cold climates. You can get a liquid heat riser replacement plate for the bottom of the intake man that routes warm water under the intake. Use a FELPRO gasket. You may have some trouble with the intake and exhaust headers being different thickness and or warping. Some of this can be solved with the felpro or it may take more drastic measures--plenty of posts on that under headers. It might be a struggle getting the header bolts in-go careful and use anti sieze for the next time. Use some copper sealant on both sides of the gasket. You may have to elongate a mount hole to fit it. Some people recommend removing the bolts and installing studs--this would seem to make the install easier. Use PB blaster and heat if necessary, dont break a bolt and follow up by breaking an easy off in your head! You will need outside help to get it out most likely. Use a left hand drill to remove the bolt or drill and retap if necessary.
IGNITION - choose your ignition. if you go with whatever comes on your 2F that will probably be good. Some like the 60 big cap distribs and a whole lot of other choices. I got a 78 small cap with coil and igniter and it makes bright blue snap snap sparks---good for me. Post up for help with wiring up the ignition if you need to. It is easy but may not be so obvious.
DRIVESHAFTS: The spacing for the holes on the mounting flanges for the 2f 4 speed transfer case are different than your old 3 speed. You can ask the PO of the drive train to send the shafts or at least the short piece that attaches to the transfer case front and rear
This will slide into the old 3 speed shaft but since the 4 speed is longer the old shaft will be too long and will need to be shortened. You can change the flange on the 3rd member side for the one that will fit the 4 speed. I have been told that it is pretty cheap to just have it lengthened or shortened. If you have the 4 speed shafts you can use the end from the 3rd member to connect to the transfer case and use your old 3 speed short pieces to connect to the 3rd member flange. A new pinion seal may be a good idea.
TUNNEL COVER - you can buy a 4 speed trans cover but will the bolt holes line up okay? You may need to oval them. Or you can use the old one and cut new holes with a dremel. Just take a sharpie and mark underneath--you will see where you need to cut the holes
FUEL DELIVERY. I do not know all the configurations but my 40 came without a return line hooked up and the 2F has one. I think mine originally had one but was removed so I will restore it. Check out the various fuel tank configs for different years, pumps too. You may need to change how the engine side hooks to the fuel filter then on to the tank. Pretty easy but be aware of it.
GAS PEDAL AND THROTTLE LINKAGE---in work but it looks like the mechanical linkage system will work. There is also a way to adapt a cable with a bracket but I will need to search on that.
Inspect for leaks and fix them before installation
Thats about it for what i have learned so far anyone else have anything to add?
Also browse the FAQs and if your keeping the 3 speed with the 2F there is info in the FAQ on how to do that
ps older sending units for oil and water temp may not cooperate with the gauges
the point is while it is not that hard it is not a straight bolt in and you may want to know some details up front to help with your decisions ( read in my case ---blunders) to save time and money.
I got some good advice from the MUD experts who you always see posting up and helping out
1st piece of advice ---try to get everything whole and complete and preferably stock --not missing accessories like alt, fuel pumps, carbs, air cleaner, cables etc. These items add up$$$
will it affect the value?---Only the purest of the purists would object to a 2F 4 speed most folks seem to like this route or the SBC
I did it in my 71
A few words of advice (ok turned out to be many words)
SWAPPING OUT A 1F 3 SPEED FOR A 2 F FOUR SPEED
CLUTCH---You can choose to use your finger style clutch set up-older type but use everything together --bell housing, fork, fork pivot, throw out bearing etc or you can upgrade to the diaphragm newer style clutch
heres a post that shows them both and a rear main seal which you might as well do now as well:
https://forum.ih8mud.com/40-55-series-tech/245021-pics-oem-p-ns-rear-main-clutch-change.html
I got all OEM from CDAN with RMS for about $400, order an extra clip for the throw out bearing retainer--that little bugger runs away!
with the 4 speed the slave cylinder is on the rh side but the pivot, fork, and cylinder can be moved to the LH side sweet and easy or make new lines from your clutch MC to your slave cyl
EMER/PARK BRAKE---decide what you are going to do about the parking brake. The 4 spd is longer and you will probably not be able to get the drum off once the drivetrain is installed cause it is real close to the crossmember. Obtion B is to cut and turn the cross member. Or you can remove the rear motor mounts each time you service the parking brake. I personally dont consider LINELOCK as a viable option because it would not make a good emergency brake. I recently found out the MAF brake will not fit either----and it is not cheap, OUCH!
Also you will need a parking brake cable to suit both your park brake drum and the handle end---this is different for different years. I think the 76 model satisfied my prob but check with the supplier for advice on your year model . You may receive the drivetrain with the cables cut
The good news is the drum brake set up will probably not need servicing for a long time if ever if it is working but what if you break a cable? FAN SHROUD --- 2F Fan may stick out further, a 1F pump would fit but you lose the oil cooler if you have one and you only get a metal 4 blade fan and probably only one pulley---you may need 2 for power steering. Another option is the water pump/pulley/fan combo. I got a 76 clutch fan with a 7 blade fan. I lengthened the rad mount holes on the chassis so I could slide it forward slightly. I widened the shroud a little too by cutting out the connecting strip of metal on the bottom and bolting in a new piece that is slightly longer. I am told the AUSSIE 8 blade fits fine without any mod but MAF was out of Stock, CCOt ALSO. You can buy a 2F shroud or some folks run with no shroud but I didnt want that.
SPEEDOMETER CABLE. I used the 1F one so it would go into my speedo housing the 2f one didnt
ALTERNATOR - I ordered all the RH mount stuff from SOR including bolts and a two pulley water pump pulley. I did this so I could do PS mod later. I ordered the adjuster bolt but I cant see how it works with the Inter Volt reg Alternator I got but the mount works fine. A 1F alt will not work unless you change the front face to the straight clocking instead of off set. I also ordered a external VR alternator by mistake and all that will take is re-routing the wires. But the internal VR mod is easy. I don't like seeing the batt cable straight to the alternator it is safer to use a fusible link here.
DESMOG? If you decide to DESMOG you get rid of a bunch of clutter. Some of the smog stuff may not be with your early model since it may be fender mounted. For Desmog Jim C and Mark A are the acknowledged experts and will PROBABLY need both the dizzy and carb to do it right--BUT ASK THEM. When you remove the air rail there are nice OEM allen plugs to take their place or you can get some square head brass plugs from ACE with slightly different threads but they screw right in and work. There are a couple good posts on DESMOG and I think an FAQ.
EXHAUST- if you go with headers you will lose the warm up feature of the OEM manifold which has a butterfly to route warm air up to the bottom of the intake manifold. This may cause long warm ups in cold climates. You can get a liquid heat riser replacement plate for the bottom of the intake man that routes warm water under the intake. Use a FELPRO gasket. You may have some trouble with the intake and exhaust headers being different thickness and or warping. Some of this can be solved with the felpro or it may take more drastic measures--plenty of posts on that under headers. It might be a struggle getting the header bolts in-go careful and use anti sieze for the next time. Use some copper sealant on both sides of the gasket. You may have to elongate a mount hole to fit it. Some people recommend removing the bolts and installing studs--this would seem to make the install easier. Use PB blaster and heat if necessary, dont break a bolt and follow up by breaking an easy off in your head! You will need outside help to get it out most likely. Use a left hand drill to remove the bolt or drill and retap if necessary.
IGNITION - choose your ignition. if you go with whatever comes on your 2F that will probably be good. Some like the 60 big cap distribs and a whole lot of other choices. I got a 78 small cap with coil and igniter and it makes bright blue snap snap sparks---good for me. Post up for help with wiring up the ignition if you need to. It is easy but may not be so obvious.
DRIVESHAFTS: The spacing for the holes on the mounting flanges for the 2f 4 speed transfer case are different than your old 3 speed. You can ask the PO of the drive train to send the shafts or at least the short piece that attaches to the transfer case front and rear
This will slide into the old 3 speed shaft but since the 4 speed is longer the old shaft will be too long and will need to be shortened. You can change the flange on the 3rd member side for the one that will fit the 4 speed. I have been told that it is pretty cheap to just have it lengthened or shortened. If you have the 4 speed shafts you can use the end from the 3rd member to connect to the transfer case and use your old 3 speed short pieces to connect to the 3rd member flange. A new pinion seal may be a good idea.
TUNNEL COVER - you can buy a 4 speed trans cover but will the bolt holes line up okay? You may need to oval them. Or you can use the old one and cut new holes with a dremel. Just take a sharpie and mark underneath--you will see where you need to cut the holes
FUEL DELIVERY. I do not know all the configurations but my 40 came without a return line hooked up and the 2F has one. I think mine originally had one but was removed so I will restore it. Check out the various fuel tank configs for different years, pumps too. You may need to change how the engine side hooks to the fuel filter then on to the tank. Pretty easy but be aware of it.
GAS PEDAL AND THROTTLE LINKAGE---in work but it looks like the mechanical linkage system will work. There is also a way to adapt a cable with a bracket but I will need to search on that.
Inspect for leaks and fix them before installation
Thats about it for what i have learned so far anyone else have anything to add?
Also browse the FAQs and if your keeping the 3 speed with the 2F there is info in the FAQ on how to do that
ps older sending units for oil and water temp may not cooperate with the gauges
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