Cummins or Cadillac?

[Woofwagon]

Mulling over either installing a Cummins or a Cadillac big block. The TBI runs fine, but is a little weak on power. I had thought that installing a Cummins would be a no-brainer but now I'm running up against transmission fitting issues, and whether the stock 10 bolt front end would handle 1100 pounds above it. One option I have been looking at is a 472/500 cubic inch Cadillac engine. Fully dressed out, this engine weighs 60 pounds more than a small block 350 yet has 500 foot pounds of torque. Cammed, they can push 600lb/ft.

The Caddy option would be a cheaper install for sure and would still mate up to the existing TH400. I would like to run a diesel, just no 6.2/6.5 engines. I'm having a hell of a time finding a Cummins for a decent price that isn't clapped out. Also the TH400 would never hold up behind a 6BT with its ultra low end grunt.

 

[east_tn_81]

To me it is a no brainer but I am sure the cummins fanboys will go crazy. The cadillac motor to me sounds like the way to go save money, weight and have more torque than a stock cummins.

 

[clandr1]

Why not go with a LS motor in 5.3 or 6.0?

 

[Woofwagon]

Clandr1, I had thought of that but I want to eliminate as much electronic stuff as possible. Plus the Cad could be built for pennies (in relation to other engines) and still have 500-600 foot pounds of torque without having to spin the engine way high.

 

[superbuickguy]

Mulling over either installing a Cummins or a Cadillac big block. The TBI runs fine, but is a little weak on power. I had thought that installing a Cummins would be a no-brainer but now I'm running up against transmission fitting issues, and whether the stock 10 bolt front end would handle 1100 pounds above it. One option I have been looking at is a 472/500 cubic inch Cadillac engine. Fully dressed out, this engine weighs 60 pounds more than a small block 350 yet has 500 foot pounds of torque. Cammed, they can push 600lb/ft.

The Caddy option would be a cheaper install for sure and would still mate up to the existing TH400. I would like to run a diesel, just no 6.2/6.5 engines. I'm having a hell of a time finding a Cummins for a decent price that isn't clapped out. Also the TH400 would never hold up behind a 6BT with its ultra low end grunt.

Stop trolling my posts!!!! :sombrero:

I'm making the same decision for my FJ40 http://www.bangshift.com/forum/forum/bangshift/project-cars-update/959224-fj4overland

difference is I already have the 500 caddy, headers and the 425 heads to make it sing. problem is I don't think it will fit as it's a wide beast... still 500 hp 650 lb torque out of a gas motor is pretty awesome

It won't mate up to your current 400, it's a BOP bolt pattern as opposed to the Chevy bolt pattern of the 6.2 diesel, sbc, bbc... did I mention I also have the transmission? the internals are the same, so you can swap your output shaft into a BOP transmission (or there are dual bolt pattern turbo 350s).

However, the turbo 400 will hold up just fine behind a 6bt. If you're terribly concerned - upgrade it to Turbo 475 internals (straight cut gears). It's what I did for my 900 hp Buick.

And just throwing this out there... I would sell the motor, heads, and trans... I'm also in the Puget sound - just north of lake washington

 

[Woofwagon]

That is a very tempting offer. I can get the BOPC/Chevy trans adapter from Jegs for 60 bucks. My primary thing about the 6BT is all the suspension work to be done to handle that amount of weight.

 

[east_tn_81]

If you got the money go for it. It seems like you will spend more to buy the cummins and the even more to fix it and more to prepare the ride for it. If money is not the issue the cummins is a great way to go. How much more down time would you have if you went with the cummins vs the caddy motor?

 

[Woofwagon]

If you got the money go for it. It seems like you will spend more to buy the cummins and the even more to fix it and more to prepare the ride for it. If money is not the issue the cummins is a great way to go. How much more down time would you have if you went with the cummins vs the caddy motor?

I honestly wouldn't know. As an engineer, I like to keep things simple. While the Cummins would be an awesome setup, I don't want my Suburban to languish for over a year while accumulating the parts for the conversion. The Cadoo motor is looking better all the time.

 

[east_tn_81]

I honestly wouldn't know. As an engineer, I like to keep things simple. While the Cummins would be an awesome setup, I don't want my Suburban to languish for over a year while accumulating the parts for the conversion. The Cadoo motor is looking better all the time.

I get that for me I do not want a project to sit i want to use it.

 

[clandr1]

Clandr1, I had thought of that but I want to eliminate as much electronic stuff as possible. Plus the Cad could be built for pennies (in relation to other engines) and still have 500-600 foot pounds of torque without having to spin the engine way high.

Gotcha. I'd opt for the cadillac motor then. I'm not sure how the truck would handle the weight of a Cummins. Another alternative would be a 6.2L J-code diesel from a mid-80's CUCV. Those can be very reliable with the right maintenance/mods, and would almost be plug and play.

 

[superbuickguy]

That is a very tempting offer. I can get the BOPC/Chevy trans adapter from Jegs for 60 bucks. My primary thing about the 6BT is all the suspension work to be done to handle that amount of weight.

at one point this motor was in a chevy truck, frame, the body was 54 Studebaker. As such, it's got the right pan on it (forgot to mention you need to swap pans too)... I'd do the adapter route too, rather than change all the internals. That said, T400s can handle an amazing amount of hp and torque - so don't let that stop you from the swap. The Cummins weighs in at 750 lbs, the BBC 600, sbc 550 and the Cadillac at 550 as well. Honestly, the only bracing I would do for the cummins would be to tie the transfer case to the motor with the rod that everyone takes off of the 208... worst case scenario is you'd need a midplate to take the stress off the 400 (balancing the weight between the motor and the 205 can break the aluminum case)... heck, the 205 weighs nearly 300 lbs...

with all of that said, I saw a bus detroit diesel in a 75 Chevy truck, it took some bracing, but it was in there with the best Granite falls engineering there was (think red neck that goes from toes to tip of the head)

 

[Woofwagon]

The 6BT Cummins weighs in at over 1000 pounds fully dressed. That is a bare minimum weight. I love the Cummins engine, it's a real engineering marvel. It's the mass that I'm having a hard time noodling over on the suspension. For the frame crossmember to clear the balancer of the Cummins, I'd have to torch out a 13" cut.

 

[superbuickguy]

The 6BT Cummins weighs in at over 1000 pounds fully dressed. That is a bare minimum weight. I love the Cummins engine, it's a real engineering marvel. It's the mass that I'm having a hard time noodling over on the suspension. For the frame crossmember to clear the balancer of the Cummins, I'd have to torch out a 13" cut.

and my noodling is over whether or not it will fit (the answer is actually, no, it won't without a lot of cutting)... however, I have to back myself into a SBC. You're right on the weight, I was thinking 4bt... sorry. I've got a couple other projects ahead of the FJ, so there will be much noodling, posting, and discussing before anything is set in stone - as far as power wise - part of me thinks 4bt or even a 300tdi (as I do have experience with those) with the Aisin 5 speed I own.... 200 hp, 400 lb torque - it wouldn't be fast, but it'd climb anything and get 30 mpg while doing it.

 

[Woofwagon]

I'm not having much luck either finding a 4BT locally. Seems a lot of truck owners are twigging to this Cummins conversion. The 4BT is a noisy, shaky engine though.

 

[east_tn_81]

So if you go with the caddy motor are you using a carb?