Hot Rod Forum banner

455 vs 500?

3K views 7 replies 4 participants last post by  HemmiGremmie 
#1 ·
I posted pretty much the same post on the MTS message board for 500 caddy fans.

Basically I am getting a 72 cutlass with a 455 in need of rebuild. Actually the whole car needs to be put back together almost, but that is another several posts. But I find myself debating the powerplant. Like I said the cutlass has the 455 olds motor in need of a rebuild. But I also have a line on a 500 caddy out of a 72 eldorado. One thing that would make the swap easier is that the front sheet metal is off. SO now is the time to decide this stuff.

The price I can find on rebuild kits for the 455 is roughly 4-500 dollars. This includes cast pistons, which with the driving I do would be enough for my needs. Any better prices or is that about what I can expect?

The 500 probably could run as is for 325$ (roughly). But then I would have the expenses of oil pan and exhaust work. BTW the 455 does have headers so it is good to go from an exhaust stand point. But the 455 would need machine work.

From a price stand point they are probably about equal when everything is added up, with maybe the 500 being a little cheaper. I am leaning toward using the 455 if the block is good. But I have always wanted a 500 caddy powered ride. And I have heard that the 500 gets a little better gas mileage. Neither is an economy motor though.

Main use would be basic driving, not hard racing. Except maybe from stop light to stop light. I basically want a good solid motor with low end power. Either would do that. I just want opinions on what you would do. Helps me figure out what I want to do.
 
See less See more
#2 ·
you have got me on a lock between two motors i love.

Thank you for not going with the chevy i must say (i do like the chevy but i find it in too many olds, cati, and buicks which shouldn't happen)

My opinion is stick with the olds 455. if cost is your concern and headache then you shouldn't go with the 500 because you would have to buy too many conversion parts for it to work and i don't think there are many parts companys that will change a 455 olds to a 500. However they are both GM so i really don't know if it is easy to change them or not.
 
#3 ·
The easiest part is that the trans bolt pattern is the same. I would have to fabricate motor mounts and really work on the exhaust manifolds/headers. Those are the two main areas of concern aside from the oil pan. Plus the steering might need to be moved for the exhaust. It would be a pain, but I would probably go that way if the block is not sound.

[ October 21, 2002: Message edited by: Wmarden ]</p>
 
#4 ·
I've read in the past about putting Caddi engines in G-body's. The real problem is the exhaust manifold on the driver's side. all sorts of things have to be "tweeked" such as the steering shaft and upper A-frame. I really don't have a clue if there will be a problem in your auto but I bet between the oil pan and exhaust manifold there will be some sort of problems. Your best source it to e-mail MTS. I'm very sure that they will know exactly what you're dealing with. Also, don't forget that unless you get the smaller chamber heads, that 500 will be a slug, but I'm sure you know that! If you want ease of installation with no surprises, then go with the Olds. Incidently, I put a 455 in my 81 Cutty. What a piece of cake, easy job! Every thing fit, including the crossover exhaust pipe under the oil pan to the passenger exhaust manifold and then it even lined up the the catalytic converter!
 
#5 ·
I am going to go with the 455 as long as the block tests out allright. I am bringing the cutlass home today. Also it turns out it was a 71, not a 72. But close enough for government work. Already got the title over here. Just need to clear out some space for it in the basement.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top