73 FJ55 Transmission Swap (with 350 SBC) (1 Viewer)

[jerseypiggy]

I have a 350 SBC in a '73 FJ55 mated to original T-case (I believe) and original 3-speed tranny (with various adaptors and cross-members, etc). Speedo and e-brake are already gone (and I'd like to get back/working).

I want to go 5-speed manual 4x4...not for offroading/crawling but to do road-trips via highways. I have posted elsewhere and have spent hours reading...but there's a whole bunch of FJ40 and Cummins diesel input that is distracting.

What are (best) options for keeping it straightforward to mate up the 350 SBC to a 5 speed manual 4x4 tranny (eg: NV4500 or H55F)? I will consider 4-speed (eg: SM465) if its MUCH easier in terms of no/cheaper adaptors and no custom work and not having to replace or cut axles, shafts, etc.

Thanks.

 

[scrapdaddy]

Good looking wagon. Do you know what bellhousing (adapter) you have? To run the H55, you will need a newer transfer case (split case). I'm running a Chevy 5.3 with an Advanced Adapter bellhousing, H55 and a 1986 split case. The NV4500 is a great tranny also, but requires different transfer case, etc. I guess the first step would be to figure out what you have and what you want to spend, as it can expensive, driveshafts, etc.

HTH,
Ron

 

[jerseypiggy]

[QUOTE="scrapdaddy, post: 10552726, member: 67856"... the first step would be to figure out what you have and what you want to spend, as it can expensive, driveshafts, etc.HTH, Ron[/QUOTE]

Here are some pics... That looks like the Adanced Adapter crossmember support kit... Can you help me ID the other parts of the drive train?

 

[jerseypiggy]

More...

 

[3_puppies]

I'd say your rear driveshaft is too short.

the rear crossmember is the common propeller mount, some have had issues with cracking on the outer ears.

not sure who did the conversion but some things look abit sketchy.

 

[jerseypiggy]

@Lil'John , I got all the adapters and bellhousing etc etc etc etc to support a new 350 SBC crate engine and a new NV4500 tranny. Have trimmed the nipple on the NV4500 and expect to get a new driveshaft machined but cant seem to get the components into the available space--not enough clearance (the NV4500 being much bigger than stock). I have already gotten new shackles to add a couple inches but that doesnt seem to be enough.

Must I do frame-off? I got some rust in one rear fame/body support section that I'd much rather not put to the test just yet.

How do you get this to fit without removing the frame? How much cutting of the floor is to be expected?

Thanks much,

 

[jerseypiggy]

thanks Lil'John. Still working on this. The NV4500 (assuming heater core stays where it is and shifter tower is not jammed fully against it) runs much further back than stock...so the 28" propeller crossmember (Adv.Adapters) doesnt reach. Am I missing something or do I somehow need to fabricate a crossmember (despite having bought one already!)

TIA

 

[Megadoomer]

Is your nv4500 a 4x4 tranny? The 2x has an extra snout at the end. I wonder if that is the issue?

 

[jerseypiggy]

4x4...its not just longer, its also taller/bigger...by about 4"...so looks like i either need to create a tranny hump in the cabin or i gotta install the entire drivetrain 4" lower...and therefore need to liftkit the entire pig to maintain decent clearance. and the extra length makes the crossmember more or less useless...thinking we need to fabricate extensions to it or steel boxes to move the braces further off the frame rails. certainly not a plug'n'play situation.

 

[RUSH55]

Been looking at this myself as will possibly going this route down the road.
I think you’ll need to cut your current t-case mounts and cut the back part of your tranny hump mount and set it back accordingly. Can’t remember offhand the length of the nv4500 but several inches longer than the 3 spd trans for sure. I’d measure from the bellhousing mating surface on the 350, to the back of the highest spot on the trans to see how far you’ll need to set that rear section of tranny hump mount back. Thinking it should be about 3 - 4 inches. Might have to sacrifice your rear heater - maybe not.(?)

 

[RUSH55]

Not having to cut the hump mount would be great - I think it’s close, but maybe like you say, that inch or so forward the V8 sits allows the tranny to fit that space without modifying.

 

[jerseypiggy]

well @RUSH55 and @Lil'John et al, we were able to use a fabricated crossmember and get tranny secured and connected to tcase/engine...

now the issue is that the drivetrain cant just be swapped front /back (as was rumored) but one needs lengthening and the other shortening (OK) but ... to quote my mechanic:

"Got a call from driveshaft shop, may need to convert the front one to a double CV joint due to the angle of front diff & drive line angle. The engine/trans has about a 6 degree downward pitch to fit under the firewall without having to cut into it, it's causing the front pinion flange of transfer case to face upward and from factory, the front diff flange faces upward as well. The guy at the drive shaft shop said that it may cause driveline vibration so he's going to price out what it would be to do a double joint on the front driveshaft."

Normal? Avoidable?