CJG

ok, so we are still trying to get this motor done. I have a 455 block. I believe it is .030 over. I believe it to be in need of a complete rebuild. We are on a budget like many people are. I want to strip it down and have it all cleaned and checked out. I found an original 425 crank, reconditioned 425 rods, and complete original 425 B code heads all for about $400. Am I correct that if I have the crank cleaned up, use those rods, buy a set of decent 425 Pistons to fit whatever bore we end up with, and have the head gone theough etc, that this will all go together and make a 425? I would have to choose from limited cam choices I have read, and would get good internal bearings etc. would I need special pushrods or lifters? Any suggestions on what to do to the heads or cam choice? I'll have to buy an intake and maybe carb. Hoping to make 500 ft lbs torque and 400+ hp on 91 octane pump gas, and spend $3000 or less total. Any help and advice greatly appreciated.

svnt442

If you have a 455 block, all standard Olds cams will work just fine. The bottom end will be 425 and the top is standard Olds 455 stuff.

CJG

So the heads being 425 heads don't matter I just need any 455 pushrods, the correct length of course, and lifters depending on the cam and rockers I used? I'm new to all of this and trying to figure out what all I need to get before taking it to machine shop.

svnt442

Lifters are determined by the lifter bore size and if it's a flat tappet or roller.

joe_padavano

Keep in mind that all 455 blocks have the standard 39 degree lifter bank angle and 0.842" diameter lifters, so any normal Olds cam and lifters work.

CJG

Ok, so I am pretty sure I am going to pick up the 425 crank, heads, and rods. Using these in the 455 block I have. Now I am sure the block will need bored, so need suggestions on what pistons, cam, pushrods, lifters, rockers, etc to look at. I want to run 91 octane, and have kind of a slower lope sound, but not crazy. I have headers and 2 1/2 inch duals with magna flows. Or if I take what I have to a machine shop, give them my budget, will they just know what to do? I get nervous after reading all this stuff about Olds engines and want to be sure the shop will know what to do to make it right lol. Am I paranoid? Just want to be able to have everything I need and let the shop do their thing. Thanks. Oh yeah, what intake and carb should I get? Have a torker and don't want to use that, and only have a small 600 cfm edelbrok carb so need to go bigger there. Need easiest/maintenance free as we can get with the carb. also have hypertech HEI so should be set there.

joe_padavano

Just because you're paranoid doesn't mean that they're NOT out to get you...

Seriously, unless the shop has a track record of building Olds motors, don't expect them to understand the nuances, ESPECIALLY on a mixture of parts like this. The biggest thing that could become an issue is that despite the common bore, the pistons are NOT the same, due to the different compression heights. The 7" rods that go with the 425 crank require a shorter compression height on the pistons.

CJG

Ok, so then would the machine shop have to determine that after doing the machine work and taking measurements? Should I just look for all 455 stuff instead? Just trying to do this as affordably as I can right now. I know of a local machine guy who had built many Olds drag motors for a guy I know. I'd think he could figure the stuff out but not sure.

cutlassefi

You won't make that with the parts you have. Why not just buy a used 455 crank and rods somewhere and sell the 425 stuff?
Which ever way you go you'll need a 750 or better carb, a Performer intake and a fair bit of camshaft in order to really make the numbers you want. Sorry.

CJG

Don't be sorry. I have no idea what im doing so any advice is greatly appreciated! I just could get the 425 stuff cheap so figured i would look into that. I have another guy wanting to sell me a 455 N crank 425 rods and pontiac pistons for another set up for a grand. That sounds kinda out there but maybe it would work? If you had 3000 buck to spend what would you do in my case? Besides save up more money lol

cutlassefi

You could use that combo but depending on which Pontiac piston is with it it may come up a little short, and/or be the wrong bore size. See what he wants for just the crank and go from there.

CJG

.030 iCON PISTONS PONTIAC 455

Not sure I really want to go .060 over on the block though...

cutlassefi

Again WHICH Icon piston. They make more than 1.

CJG

That's all the info he gave me. Not going that route anyway. Found machine shop I trust. Talked to a local racer who runs all old Olds stuff in his Cutlass and he got me ahold of the guy he uses. Gonna get the block checked first to make sure it's good to go, and in the mean time do more research. May just try to find all 455 stuff instead of the 425 just to make things alittle less complicated. One more question, would it take just about as much $$ to have a set of say C 455 heads re-worked to flow as much as a set of Edelbrock aluminums out of the box? Would I be way better off just getting a set of aluminums or can the stockers be cleaned up and built to flow plenty good for a lot less?

cutlassefi

I'd do the aluminums anyway, no sense in putting a bunch of money into the irons. After you're all done you still have 50 year old heads and technology.
You can get Edelbrocks or I offer the Procomps, with mild porting and upgraded pieces throughout. Plus they come with 2.125/1.68 valves and are cut to your desired CC. Price is $1795.00+ shipping.

CJG

Ok. Thanks for the advice. Hope you're not having too much cleanup down there from the storm, and hopefully these other ones stay away!