Caddy 500

This page is to give information on swapping a 500ci Cadillac engine into my 1982 Monte Carlo. Other similar engines and bodies will be discussed somewhat. As either the ideas for this project or the actual carrying out of the project progress, so will this page.

(An article from) HOT ROD Magazine, November Volume 52 Number 11
"Cadillac V-8 into '78-'87 GM Intermediates: Do the Twist"

"Plentiful and cheap, the Cadillac 500 is an absolute torque god that weighs in at a mere 595 pounds, complete-40 pounds more than a Chevy small-block! If images of an El Camino, Monte Carlo, Cutlass, Regal, or Grand Prix bombing down the street sideways (its rear quarters enveloped in a wall of whiteness) come to mind, you're on the right track. Thanks to companies like Cadillac Motorsports Development (CMD) and Maximum Torque Specialties (MTS), Caddy-to-GM intermediate swap kits are readily available; the universal-fit swap kits stick a Caddy into virtually anything on wheels. Either company can supply the proper motor mounts, brackets, pulleys, and oil pans, as well as a comprehensive gathering of headers, cams, pistons, and intakes if you want to dig in and really make the Caddoo haul ass. Trust us, Caddys are hot. Otherwise, why would Edelbrock introduce an all-new dual-plane intake manifold (PN 2115)? The icing on the Caddy cake is that very few changes to the recipient are required. Aside from the swap kit mounts, transmission crossmember, and oil pan, all you'll need is a non-Chevrolet TH400 and some head pipe reworking to match the Caddy manifolds. The stock GM 7.5-inch rear axle is pretty lame, but can be fortified with posi and lower gears, or replaced with any '68-'72 A-body 10- or 12-bolt axle equipped with HP Motorsport lower control arms."-From "Cadillac V-8 into '78-'87 GM Intermediates: Do the Twist", page 47-48 of HOT ROD Magazine, November, Volume 52, Number 11
According to other information from this same issue, the first choice of a Caddy engine would be a '70 to a '76 500. However, '68 to '74 472's and '77 to '79 425's also work well. CMD and MTS both make parts for these engines. With high performance parts, a Cadillac engine with 425hp and 590lb-ft of torque can be built for 1/3 the cost of building a big-block Chevy engine the same way. Big-block Chevy headers from '78-'87 Chevy big-blocks must be used with the 500 Caddy engine. They are adapted to flanges that come with the kit. In one day the Caddy swap can be done with the proper kit, headers, tranny, etc.

The following comments on the Caddy swap can be found on the message boards at www.MonteCarloSS.comand only bits and pieces of these whole ideas are posted here.
"I'm REALLY leaning towards swapping a big Cad into my next SS project. I figure it would be fun for a daily driver, and if the other G-Body Caddy swap I've seen are any indication, it will be FAST too. Remember, a stock Caddy 500 puts out 500ft/lbs of torque w/ pump gas compression ratio. MTS makes a kit to bolt Caddy and the Turbo 400 right in. Swap the 3.73 or 3.42's for an EASY to find 2.41 rear and watch out!! Also, the big CAD only weights about 60 pounds more than a 350 when you use a Edelbrock alum intake... add 40 pounds or so for a stock cast iron version. And the best part so far is COST!!! I've run across MORE than a few RUNNING and driving Caddy's w/ the good 472 or 500 for CHEAP!!! With traction, LOW 13's high 12's w/ highway gears and the Cad motor is very attainable. I think it would make a fun daily driver.

Let me know what you think

(Others in response)
"I've been following a similar post on the gbody mailing list too. I have been kicking around the idea of putting one into my beater buick. those caddys are all over the junk yards. I would love to see one in a g-body but I prefer an SS with a small block chevy."

"Do it. It's cheap, light-weight power. Let the small-block people whine all they want, then give 'em a nice long look at your tailights.

As I've always said, so long as it's GM, it's still in the family..."

"The 70-71 500s are the best by far, I think they put out about 300-350 horsepower and about 510 torque, but any 500 will put out a ton of torque. It's just that by about 75-76 they put out about 180 horsepower. If you're looking for the cheapest power with minimal mods to the engine, I'd definitely go with the early 70's blocks. However do keep in mind the different ways horsepower was rated prior to 1972. Still, taking that int account, the 70-71 blocks are better."

"I am kinda waiting for one of those to come my way as well. The biggest draw back is that the distributer is on the wrong end of the motor."