1967 wagoneer th400 with factory adapter 350 Chevy swap

[123456]

My Jeep has one of the early th400 with a factor adapter plate. My plan is to swap the Buick 455 it currently has for a Chevy 350. I was looking for an adapter kit when it occurred to me that if I take the factory adapter off shouldn't a Chevy 350 bolt up to my trans if I get a chev converter and flex plate?
Has anyone tried this?

[tgreese]

No, only the old-old Buick nailhead engines will bolt directly to the existing transmission. And if you remove the adapter, you won't have room for the convertor, since the nailhead blocks stick out the adapter thickness to meet the transmission case. Since you have the Buick 455 big-block engine, you must also have the nailhead-to-BOP (Buick-Olds-Pontiac) adapter used with the Jeep 350 engine. Both of these patterns (nailhead without the adapter and BOP with the adapter) are different from a Chevy. Jegs or Summit sell an adapter plate from BOP to Chevy that should adapt the BOP adapter to the Chevy engine. But it won't just bolt up.

https://www.jegs.com/p/JEGS/JEGS-Engine ... 4/10002/-1

[lkmarsh]

Someone near you must have done an LS swap into their Chevy 4x4 recently, so there should be
a Chevy-pattern 4x4 TH400 available. Not that much more work, and you could sell the Buick
engine and trans as a unit. One option among many.

[Crankyolman]

Like everybody else said, the original transmission was the GM "Universal" transmission which had the unique nailhead Buick bolt pattern. The solution for swapping to a Chevy is to find a TH400 with a Chevy pattern. It doesn't need to be 4wd it just needs to be a Chevy pattern 400 but if it comes with a transfer case with a right hand drop you could use it. The problem there is you may need to get new drive shafts. If you want to keep your transfer case and drive shafts the easiest and cheapest solution is to get a TH400 without a transfer case and take your original trans apart and swap out the output shaft for the one that fits the Dana 20 transfer case you should have, then you don't have to get new drive shafts.

Here is one example of someone who did the output shaft swap, although it's for a quadratrac and not a Dana 20
https://seattle.craigslist.org/skc/pts/ ... 98008.html
But other Chevy pattern TH400s are all over Craigslist

[fsj454]

Hi and I stripped a 1975 Cherokee years ago that had a chevy 350 motor . I still have the turbo 400 hooked to quardra trac under my bench if that is what you need

[tgreese]

I don't understand what's so appealing about the Chevy 350. It's just an old carbureted pushrod V8, like any of these we've been discussing. If I were to spend the time and money to swap, I'd go with a modern Chevy drivetrain with a modern MPI engine and a modern overdrive automatic and a modern chain-drive transfer case. Go big or go home.

[lkmarsh]

There are two sides to the vintage vs. modern debate. SBCs are everywhere, so are parts,
and a large pool of experience to draw from. Cheap, simple, and the most aftermarket support.
I get the enthusiasm for newer tech, too, but it also has it's drawbacks. Aluminum everything sounds
great, but the risk of stripping threads is huge. Everything about an LS is more expensive.
I like reading about others' experience doing an LS swap, but for me it will have to wait
until I know a lot more about it than I do now.

[Crankyolman]

SBC is a lot less work and expense than a modern swap. Like I said above, a Chevy TH400 with Dana 20 tailshaft and you don't need new drive shafts, all you need are motor mounts and no computers necessary. If you want EFI you can buy an aftermarket intake set up for TBI fairly cheap and you don't have to screw around with programming. Most modern aftermarket EFI used chevy 350s to base their programming on. You can even get most parts cheaply at junk yards. Also once you do an SBC swap you have a fairly large selection of engine sizes from 283 all the way up to 400.

[Chevy powered Chief]

The 455 has a different bell housing setup. Try http://www.novak-adapt.com. Maybe a big block GM is a better fit seeing it's modified already for a 350. I went with the 89 Chevy 350 TBI an NP205 twin-stick Transfer case and a GM 400th trans.