: good mods for under $1600?



cadillacdeville
07-30-04, 02:26 AM
Ok, I've got 1600 dolars to invest in my 1977 cadillac 425. would new heads, cam, manifold intake and exahust, also true duel exhaust be a good investment for decent power? :brutal:

davesdeville
07-30-04, 07:14 PM
You're not gonna get "new" heads with that bugdet. Ported heads with larger valves are doable, along with intake, cam, headers, and duel exhaust. They'll all help. 75 extra CI couldn't hurt...

lux hauler
07-30-04, 08:15 PM
My suggestion would be to look around for a good, running 472 or 500. The 425 isn't a bad engine but the 472/500's will bolt right in. You might have to swap the oil pan and pick-up tube from the 425 but that's about it (eldorado engines had different oil pans and a different driverside exhaust manifold). There are lots of '68 to '75 Caddys out there that are rust heaps but still run good for very little money. $500 should buy the whole car. Yank the engine from the donor car, clean it up, change what needs changed and drop 'er in. You can use the 425 motor mounts, the tranny bolts up the same and the external dimentions are basically the same......instant power increase.
If you must keep the 425, I'd start with a better cam, intake manifold, carb built to match the engine combo, headers and exhaust. That should put a pretty good dent in your budget. I've heard the 425 heads can be improved with some port work and valves but that can get into lots of money real quick.....as a matter of fact, you could probably blow your whole budget just on the heads. Don't forget, to make "good power" and to be reliable, the parts need to work well together. Just "throwing parts" at the engine could cause you head aches. Make sure you plan your approach. Know what you want the engine to do and how much you can spend.

cadillacdeville
07-31-04, 02:51 AM
Well I was told that the car was rated at 180 hp and 320lbs of tourque now thats what the factory said it seems low to me. anyway I like the tourque but that hp has got to go up from what I've gathered from the other threads I think that its the manifold intake and exahust that limit the power or is it because of the compression?

lux hauler
07-31-04, 06:34 AM
Well I was told that the car was rated at 180 hp and 320lbs of tourque now thats what the factory said it seems low to me. anyway I like the tourque but that hp has got to go up from what I've gathered from the other threads I think that its the manifold intake and exahust that limit the power or is it because of the compression?
The low horsepower rating is the product of many things.....restrictive air and fuel intake (intake manifold, head design, valves), restrictive exhaust (exhaust manifold and exhaust system, head design, valves) and cam design.....improve those and it'll run better. The engine is an early emissions engine.......no one was making power in the late 70's.
It sounds like you're happy with everything except the numbers? Forget about the numbers. Enjoy the car.