BB 427 pistons

[Nasty_Nate]

Hey guys, been awhile.

Anyway, I've got a 68 - 69 gm pass 427 that i'm looking to rebuild for my car, it's currently at an engine builder getting the block bored to .060. problem being I'm having a hard time looking for a cheaper set of pistons. I've been on Ebay for a couple of months now and no luck. It's an open chamber engine, with 116.9 cc heads, and I'm looking for a ballpark compression ratio of 9.8-10.5
Anyone know of a good place to look/call/find a set of pistons for this thing?

This car is going to be a screamer, if I can just find something to fill the jugs!

Thanks
Nasty

[Nasty_Nate]

also will a set of the same era 454 pistons work for the same engine without changing the crankshaft?

[MrPbody]

Nate,

E-bay is the WRONG place to look for quality engine parts. You MIGHT get lucky, but odds are against you.

Are the heads iron or aluminum? Rectangular or oval port?

Speed Pro makes the better-for-the-money pistons. L2465F-xxx is listed to provide the compression ratio you ask about (10.44:1). With aluminum heads, this is border-line for 93 octane. For iron heads, it is WAY too high (9.5:1 max recommended).

Ross, SRP, WiseCo, etc. all make VERY good pistons and pretty much to your specs. $$$

If you're trying to build a BBC on a low budget, you're going to have to make some hard choices. You can build one that will live or you can build one that makes power. On a small budget, you can't do both. Unlike small blocks, BBCs are expensive to build, especially when you start talking big power.

No, 427 and 454 pistons don't interchange. The pin is in a different place in relation to the top of the piston.

Tell us more about what you want from the car/engine, and we can make some solid recommendations.

Jim

[Nasty_Nate]

First off it's a 427 69, oval port engine, iron heads. the heads are being ported and polished as well as the offy intake is being ported. The heads are going to be decked .015, with the intake going down .007. it has the origional steel crank which was re-ground to .020 undersize, with eagle connecting rods that were previously balanced to the .030 piston that were in it. At the moment I've been thinking about bigger valves and/or larger ratio rockers (that'll probably happen after i accually buy the cam i'm looking at (.502/.512).

I am on a slightly smaller budget, currently i'm trying to keep it under $3000. I picked up the engine off of a local guy for $800 and it ran for a short time before starting to knock, so I decided to rebuild it before it was too late. I've done a couple small blocks, but this is my frist big block, so any other info would be great!

Thanks again,
Nate

[MrPbody]

Nate,

There is very little 'porting" needed by the oval port heads. Their biggest advantage is high mixture velocity at lower engine speeds. By installing 2.190 intake and 1.88 exhaust valves, and doing a bit of "bowl work", you will get the most out of them possible. Use the valves for a factory rectangular port head. ("high performance") The 1.73:1 rocker ratio is fine.

The cam is an area of misunderstanding. BBC heads LIKE a lot more lift than small block heads. The .510 lift is an "RV" or stockish cam. .550" to about .600" lift for a flat tappet cam are not unusual in the BBC. Highly recommend Comp solid lifter cams. 294B-8 is a great grind for this in a high performance application.

Rethink the Offy intake. Performer RPM would be far superior.

ALL true 396s and 427s came with forged steel cranks. The only cast crank that would "fit" came from the infamous 402. 454s are another matter.

Jim