I just got a great deal on a 425 caddy motor (free) If I am right I can use a Th400 with a dana 20 from a jeep behind it I couldn't find anything on this swap if any one has any info it would be helpfull

Originally posted by HarleyM
If I am right I can use a Th400 with a dana 20 from a jeep behind

Is the th400 a BOP? I may be wrong but I believe you'll need one of these BOP (round top) th400s and a Caddy adapter between the transmission and engine.:D

I'm just finishing rebuilding my caddy 425 for my scout

there a good engine, good power, lots of nickel in the block and ther 100 LBS lighter then the 472/500


I also got my 425 free with it mating TH 400, but to add a transfercase you need the 400 with the BOPC belhousing


I went to the wrecker and picked up a good TH 400 with an NP 203 behind it out of a 78 3/4 ton Chev pickup

you will have to rip both transmissions apart and swap output shafts (put the 4wd ouput into the BOPC transmission) and then slap on the transfercase and then your race ready

you need a TH 400 that looks like this. I gues if the jeep had a buick V6 it should work :confused:

http://pics.montypics.com/pigiron/2003-09-20/1064117992_caddy_housing.jpg

That looks like the Th400 that I have, it has been stored for so long that I need to dig it out and make sure. I do remember that it is a BOP there was an adapter from it to the AMC There is a injection problem on the motor that I need to fix before I pull it from the caddy from the little that I messed with it yesterday it acts like there is a bad connection or a bad ground It could be something with the fuel system but I didn't have much time to play. The big draw back to this job of mine is time and after fixing trucks all day and sometimes all night I just don't have the ambition to work on my stuff.

HarleyM,

You may not have to change the output shaft on your BOPC transmission if it has the "standard" length output shaft. The most popular shaft, about 4", from the back of the main transmission case, will take the Jeep Wagoneer, or other Jeeps that used the TH400.The TH400 adapter to the Dana 20 transfer case will fit without changing the shaft in the transmission. I have used this adapter many times with good results.

ROS

I run a TH400/D20 out of the '69-'71 Jeep Wagoneer behind my 472. They came with a Buick 350, so the tranny was a bolt up. You can also use the TH400/D20 out of a Commando that came with a Buick V6.

as long as you stay auto your swap should be pretty easy. there are a bunch of companies that make adapters to mate any old chevy tranny to the caddy block.

If you haven't already, check out

www.500cid.com

and www.cad500parts.com

Chris

Originally posted by HarleyM
I just got a great deal on a 425 caddy motor (free) If I am right I can use a Th400 with a dana 20 from a jeep behind it I couldn't find anything on this swap if any one has any info it would be helpfull
You can use TH400 out of a caddy if it is the short tailshaft version. The dana20 off a Jeep that has a TH400 will bolt right on the back if you take the tailshaft housing off the Caddy TH400.

Harley you said INJECTION problem. If you have the factory port FI and need help there is a guy in my area that repairs the computers and is very knowlegable on them. PM me if you want his email

Might be easiest to go with a chevy t400 and transfercase and buy the $55 adapter from summit racing. Plus it would be a hassle to have a hybrid 400 blow up out on the road.

This is a 77 with throttle body injection but any advice is always considered a bonus
Hammerlock do you happen to have a part number for that adapter?

Originally posted by HarleyM
This is a 77 with throttle body injection but any advice is always considered a bonus
Hammerlock do you happen to have a part number for that adapter?

Just go to summitracing.com and search for cadillac adapter. Make sure you get the BOPC engine to Chevy tranny adapter and not the other way around.

What am I missing here, sounds like you have a Cad with BOP, and a BOP 400 from a waggy, why do you need an adapter:confused:

Originally posted by Jeff427

You can use TH400 out of a caddy if it is the short tailshaft version. The dana20 off a Jeep that has a TH400 will bolt right on the back if you take the tailshaft housing off the Caddy TH400.

what model/year caddies had a short tailshaft?

Originally posted by Hammerlock


what model/year caddies had a short tailshaft?


post 77

Originally posted by Hammerlock


what model/year caddies had a short tailshaft?
The one I have is out of a 77 DeVille IIRC. I don't know for sure what years, but it is really easy to visually confirm the difference, as the short tailshaft housings are about half the length of the long housings.

Edit- I forgot to mention, I believe Buick, Olds, and Pontiac all had short tailshaft versions of the TH400 at one time or another, and these will all bolt right up to the Caddy motor, and allow you to bolt the Jeep Dana 20 to the back.

Any other t/c's bolt up? 203 or 300?

Originally posted by Hammerlock
Any other t/c's bolt up? 203 or 300?
Not without swapping tail shafts, with the 203. The 300 I think you need special adapters to hook it to the TH400. The Jeep Dana 20 would be the quickest option. Get a Dana 20 out of a 3/4 ton J20 Jeep pick up, because they *might* have the 26 spline rear output. The J10 trucks had 10 spline rear outputs, and are pretty weak.

Good info. I would never be happy with a D20 though.

HIJACK.......Hammer how is your swap coming.......on the road yet?

Quite a lot more to do; work the last 4 months has been killer. Good news is that I'm now set up to program chips for 4L80e's. Doing all the research was a big time consumer though.

Another problem is I keep incorporating more and more ideas and doing too much cosmetically. Right now I'm tossing around the idea of going to 40's but it would take a lot of additional work on my SOA.