Build The Clustertruck Rides Again - Refurbishing a 1975 Chevota

[pb4ugo]

Is the riser on the passenger side? Did you run rams with the old exhaust? If not, the old stuff won't help. It would be hard for me to believe that replacement chinese manifolds would be that far off. Years ago, I installed cheap no name chinese manifolds and the walker Y pipe fit properly. You want them to fit right so you won't have any problems if the exhaust or engine has to be removed in the future. Forcing the Y pipe on could also create a leak.

After reading about the problems you had with the motor mounts, I'm curious, how did you determine where the rear motor mounts were supposed to go?

 

[RWBeringer4x4]

Is the riser on the passenger side? I'd cut the old Y pipe just past the Y, then see if it has the same issue. If it does, then i would question the manifolds. Of course, I think it would be hard to believe the manifolds were that off. Even Chinese manifolds have to be closer than what you describe. I would think Dorman would fit very close to stk. Years ago, I installed cheap no name chinese manifolds and the walker Y pipe fit properly. You want them to fit right so you won't have any problems if the exhaust or engine has to be removed in the future. Forcing the Y pipe on could also create a leak.

After reading about the problems you had with the motor mounts, I'm curious, how did you determine where the rear motor mounts were supposed to go?

The Dorman manifolds aren't great - they also conflicted with the block, initially. I had to grind down the casting to get them to clear and sit flush. I also had to clearance the castings around almost every bolt hole to get the manifold bolts to actually fit. All-in-all, not super impressed, and I wouldn't be surprised if the castings were off.

With regard to the motor mounts - this is a serious mystery to me. The frame was leveled prior to installation (jacked up and checked for level both across the front and rear cross members, and fore and aft on the side rails. I located the front mounts at about where the Downey manual recommends (19.5" from front cross member) then, loaded the old 283 block, bellhousing, transmission, and transfercase back into the truck on a load leveler. Once I got it where I wanted, and at the proper angle (about 4 degrees tilted rearward) I tacked in the front and rear mounts, then set the engine down on them, and made sure everything sat level side-to-side, and at the appropriate tilt. At that point, everything looked good. Looking at the mounts on the frame, everything looks pretty "dead nuts" even when looking at the positioning of the mounts on the frame. It's not like one mount since massively lower or higher than the other.

When I installed the new engine this time around, the truck was on its wheels, and everything was fully assembled (starter, gears in the T-case, clutch components, etc.) so it was probably a heavier load by a hundred or so pounds. I wonder if it may have something to do with weight distribution on the driveline. With the starter and transfercase hanging to the passenger side, there is a LOT more weight hanging out there. The rear mount on the passenger side was hard to squeeze an engine cushion under, while the AA propeller mount at the driver's side was angled up so high it was hitting the support brace on the tub. What's weird to me is the FRONT passenger side mount had the same issue as the rear driver's side mount - sitting high over the cushion by about an inch.

To me it seems like either the driveline is somehow twisted (which seems virtually impossible) or the frame is tweaked (which seems a lot more probable).

 

[pb4ugo]

I'd say your manifolds are questionable. If I had to do all that you describe just to get the manifolds to bolt on, I'd be getting a hold of Dorman. They are a well known company, I would think they would stand behind their products.

 

[velillen]

I hate dorman products. Had more than one of their products fail and has seen plenty others fail or not fit properly. but that's just been my experience with them! It is a bummer the y-pipe doesn't fit though! That's pretty much what I had planned on ordering. Suppose I could bump it up the priority list (which really it isn't that low anyways) and see how it fit with my ram horns (speedway motorsports).

Actually I cant. I forgot my ram horns are 2.5" and not 2" so the walker y-pipe definitely wouldn't fit

 

[RWBeringer4x4]

Yeah it’s quite annoying - I’ve already spent a lot of time grinding them. I am hoping once I add donuts and maybe some manifold gaskets at the heads I’ll have some room to work with. I think if I keep everything loose, tighten on the y-pipe to the manifolds, then tighten the manifolds to the block, everything should fit. The only remaining question will be whether or not the exhaust continues to conflict with the oil pan. If so, I’ll need to do some massaging - or I’ll need to cut and weld to fit.

 

[jim land]

are you using the heat riser or a delete spacer on the pass side

 

[RWBeringer4x4]

are you using the heat riser or a delete spacer on the pass side

Delete spacer

 

[1Fine40]

are you using the heat riser or a delete spacer on the pass side

I had to run spacers on both sides, although I do not have a heat riser, so maybe that is why?? Clearance to the oil pan is tight..

 

[RWBeringer4x4]

@pb4ugo

Here is another shot of what I’m talking about with the motor mounts:

If I take the bolt out of the mount, the truck literally isn’t sitting on the front passenger mount at all:

Putting the bolt in allows me to “sandwich” everything down.

Oddly enough - it sounds like I’m not the only one who ran into this - found this thread over on pirate:

sm420/3spd T case crossmember - Pirate4x4.Com : 4x4 and Off-Road Forum

Two guys over there mentioned the same issue. It’s almost like the mount is clocked wrong, but there is really only two ways it would mount, and both would be straight across.

It looks right, bolted down, in that it goes straight across.

But if I were to pop that rear driver side bolt the mount would literally lean to the point it would be almost hitting that tub brace.

That said, with all 4 corners bolted down, the engine sits level, and the frame is level, nothing appears “clocked.”

 

[RWBeringer4x4]

After a lot of fiddling, I sort of have the Y-pipe in, but would like opinions -

I’ve got about 1/8” of clearance at the passenger side corner of the oil pan between the pan and exhaust. Is this asking for trouble (heating up the oil, for example) or is this small a gap acceptable? Everywhere else clears alright.

Other than that - spent some time on the parking brake:

Threw some permatex on the drums’s splines:

Bolted it up:

Yes, I still need to stake the nut...

Next I tried to route the speedo cable out of the way:

And got the transfercase shifter installed (at least loosely) and made sure the e-brake held and the transfer case shifts through all the options.

One question: am I supposed to be able to shift from 2WD high to neutral on the case? I always though you had to shift to 4WD to get to neutral.

 

[velillen]

One question: am I supposed to be able to shift from 2WD high to neutral on the case? I always though you had to shift to 4WD to get to neutral.

Its been a bit since I played with it but I feel like I was able to go from 2wd to neutral as well. But with that bracket piece in place, it prevented this cause you'd hit the bracket before it was allowed to go into neutral which forced the normal range of 2wd to 4wd to neutral.

Looking at yours though it seems like its missing a piece that mine has...mine has a sort of "tab" that sticks up and keeps 2wd to only 2wd.
See here for what I mean
For Sale - FJ40 Transmission shifter bracket

 

[RWBeringer4x4]

Started mocking up the new radiator mount tonight - It’s another game of inches... I’d like to mount the radiator as low as possible to get the fan as close to centered on it as I can, but I still need clearance for the steering shaft.

Some fooling around:

The plan is to mount a strap across the underside of the frame. The issue is these two frame rivets (and the face that the frame is angled there, which puts the strap at an angle)

This puts the radiator about 2 inches from the fan, and 2 inches from the grill:

Ideally, I’d like to move it back closer to the grill, as the farther toward the front of the truck I go, the more clearance I get at the steering shaft. As it stands, I might have a quarter inch if I’m lucky...

This sets the radiator a little bit high still but I think it’s a decent compromise. The blades are close to the top, and head about an inch below the radiator at the bottom (about in line with the bottom of the radiator tank.

 

[71FJnick]

I think the only thing stopping the TC from being able to do 2H-N-2L is the shifter gate (bracket on the shift linkage).
From what I understand a common mod is to remove or mod the gate to allow 2L, cheaper than a twin stick setup.

 

[mtquivr]

Started mocking up the new radiator mount tonight - It’s another game of inches... I’d like to mount the radiator as low as possible to get the fan as close to centered on it as I can, but I still need clearance for the steering shaft.

Some fooling around:

The plan is to mount a strap across the underside of the frame. The issue is these two frame rivets (and the face that the frame is angled there, which puts the strap at an angle)

What about removing the frame rivet, drilling a corresponding hole in the strap and bolting it through the rivet hole?

 

[pb4ugo]

71FJnick is correct. Years ago when I still ran a stk 40 tcase I altered the shift gate so the shifter could be slid straight across from 2wd to 2 wheel low. I didn't like the idea of removing the gate all together. I wanted a stop for the shifter.

 

[pb4ugo]

I noticed in your pics that the engine is wide open. If it were me, I would either cover the intake valley and tape the intake ports or install the intake with all the openings sealed, so dirt and debris won't get into the engine. Or at least just drop the intake on without bolting it on and then covering it. Shop dirt and grinding dust gets everywhere. I'd hate to see you have issues that could have been prevented with the new engine. It's just a thought.

 

[RWBeringer4x4]

I noticed in your pics that the engine is wide open. If it were me, I would either cover the intake valley and tape the intake ports or install the intake with all the openings sealed, so dirt and debris won't get into the engine. Or at least just drop the intake on without bolting it on and then covering it. Shop dirt and grinding dust gets everywhere. I'd hate to see you have issues that could have been prevented with the new engine. It's just a thought.

Up until that picture was taken yesterday it has been covered, or, at the very least had paper towels shoved in the intakes.

I’m planning on installing the intake here shortly (the original plan was yersterday) which is why everything is open.

What about removing the frame rivet, drilling a corresponding hole in the strap and bolting it through the rivet hole?

I’ve thought about this - I’m trying to preserve the rivets, if possible - particularly those as they seem more structural. That said, there is a hole in the box frame right there, which would make for easy bolt access.

The other option is cutting he strap shorter to nest between the rails, then welding it in. The issue is the same aforementioned holes in the box frame. But doing it this way would allow me to potentially mount the strap level to the engine, instead of at the angle of the frame.

If I go with plan A, above, I’ll need to weld on some form of “wedge” to the strap to keep the radiator from being leaned way backward.

 

[pb4ugo]

Can youmake gussets/ brackets off the frt crossmember? Something like how the rad support was originally installed, but lower.

 

[RWBeringer4x4]

Can youmake gussets/ brackets off the frt crossmember? Something like how the rad support was originally installed, but lower.

That could work - my initial thinking was something like this (L brackets, or similar, mounted through the original rivet holes from the old radiator mounts. I think my main concerns were that there would be too much flex, and also that (if I remember correctly) they're blind bolt-holes, so there's no easy way to mount the bracket. It's definitely worth considering though.

 

[RWBeringer4x4]

Got a bit paranoid with the engine sitting open so installed the intake really quickly last night:

Then I had wifey help bleed the clutch. It’s pretty nice when you have the covers off and can see the pressure plate and the clutch slave cylinder from the clutch pedal:

The clutch is adjusted to the point where I (think) the throw out bearing is off the pressure plate at rest, and makes contact and actuates the plate. I’m sure there will be some fine tuning once I have the engine running.

Then, it was back to mounting the radiator:


I took @pb4ugo’s advice (not about peeing before you go...the radiator mount advice) and looked into mounting the radiator off the front crossmember. As it turns out, I can just barely reach 4 of the old radiator mount’s rivet holes and slide 9/16 bolts through.

It will be a pain holding the bolts still when it comes time to tighten everything down, but once they’re in I shouldn’t need to mess with them again.

With that, I set out to weld up some brakets. This has the added advantage of being able to bend them to compensate for the bend in the frame and mount the radiator level to the engine (which has a 4 degree rearward tilt.

I’ll have more shots of the brackets to come but here’s the start start mocking up the bends on the bottoms: