azboostin

I have decided not to go with a 396 and to either go 454 or 502.. my question is... what is different on the 502 than 454? is it jsut a different stroke and same size pistons?

Also how strong is a 454 stock crank? say out of a pickup truck ect... not sure of years. yet..


Also I am looking to make 1-1.25 hp per cube with iron heads... what are better heads to look for casting numbers ports ect... thanks

ulakovic22

iTrader: (12)

What Gen blocks are you comparing? Major difference is going to be bore. 502 has a 4.47 bore, they both have a 4" stroke and are the same dimensions.

mrdragster1970

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As said, depends on block. Big bore blocks are the best choice, cost much more.
Merlin or dart. 509" would be an excellent combination. I've also seen many excellent pieces made with a crate 502". Mild to wild.

I've know the merlin iron heads make good power. I've seen 1.5 + per inch.

Stock steel cranks are pretty good, 600-700+ HP. Don't know anything about cast. Only know one guy that tried & he was lucky.

Are you starting from scratch??

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meandmyls1

I made 580hp with a motorhome 454 bored out to 468 CI, stock cast crank, studded two bolt mains. Thats just short of 1.25 hp per cu inch.
I used World Products Merlin heads because I couldn't find a good factory set.
Good factory open chambers are 049 and 781. Those are large oval ports.

azboostin

I am talking about late 60's early 70's motors

meandmyls1

How does that change anything? I've got a 1966 427 with cast#390 heads,
a 1968 427 with cast #215 heads.
Also a 1968 396 with cast# 063 heads.
They all make over 500 hp. Easy with Large oval port heads.

All 454's I have are mid 70's to mid 80's, not much difference between them.

If you want the best information without useless stuff thrown in there how about posting more than one sentence? The more detail you give the more people can help you.

ulakovic22

iTrader: (12)

In the 60's and 70's there wasn't a 502 available that I know of, except maybe a Caddy motor. Still need to know what Gen 502 you are tlaking about, some have mechanical fuel pump provisions, some don't. Cooling systems are different, timing chains, cover bolt patterns, etc. are different. You can make good power with either but you need to figure out what you want to do first. If you go aftermarket then you can get whatever you want.

Personally I have a Gen V 502 that I bored out to 4.56 and tossed a 4.25 stroke crank in it to make a 555. Hopefully I should be around 825 at the flywheel which will be aorund 1.5 per CI and yes this will be on the street or else I would have tried to make a lot more power up top and geared the hell out of it.