A buddy of mine has a decent 47 Caddy long wheelbase coupe like this nice green one, but in primer. No engine or trans. A long term project. Needs a ton of work. My question is how much engine can you put in without twisting that frame, and how much can the stock rear end take? Probably best to go with a GM 9 or 10 bolt, LSD. 700r4 tranny. I don't mind reinforcing the stock frame, but I want to keep the build all GM. Im thinking a torquey Caddy 390 with three deuces (380 lb.ft.), or a Caddy 429 (410 lb ft.). Those are SAE net figures for fresh rebuilds. Thanks!
I would go the 390 , you can add triple carbs. Even a 331 with dual quads would do me. You can dress up with some Edmunds bits and it’s traditional and within the boundaries. How fast do you need to go?
390 it is. 3x2s. Old school GM everything. A 50s style hop up sleeper. All stock body & trim. Engine turned dash.
Shit...the frame on that Cad is probably stronger than most new truck frames. That was the best GM sold and they weren't skimping on weight back then.
Appears to be large 'C' body, series 60/62, with pontoon door caps. It's plenty strong with large central 'X' member and deep rails on 129" WB. A Cadillac in a Cadillac would be nice. If you use a later Caddy Mill it'll come with a T400 otherwise you'd need to adapt a 700R4 hoping that it handles the torque. www.wilcap.com/cad.html www.transmissionadapters.com/collections/cadillac www.cadillacperformance.com/product-category/transmission/transmission-adapters/ IMHO, the OEM rear axle would most likely be OK if driven sedately with an earlier engine however a later torque monster, 472/500, would push the strength boundaries so a later (Stronger) rear axle would be better suited as they're designed to be behind those engines. Other axle housing are easily adapted to your leaf springs with new saddles. I've seen later OT frame clips with disc brakes & PS used however I'd look at improving braking and steering only when necessary. Engine mounts and a transmission X-member are easily fabricated for use with OEM frame. http://cadillac.oldcarmanualproject.com/manuals/1947/1942-1947/index.html
I'm assuming this chassis is the same as on Buicks. I would box the outer frame rails to stiffen it up a bit. From there, you can install the rear end of your choice with a 4 link and coilovers at the rear. See my Buick thread for ideas on how to do that. The front end is your call. I won't open that political can of worms.
Well here’s a couple of ideas...Buick 320 or a nice Hungry Ford just to bring back balance into our hobby!
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