What pistons to use

[CarsByCarl]

Originally Posted by racedraper

its a 68 429 c9ve block and heads, the heads are 72cc if im correct. I want to stil use pump gas. its for my wifes car that she will drive on weekends. I want good HP but not enough that it will scare her. So does this help.lol

If you plan to retain the 429 rotating assembly, piston choices are going to be somewhat limited.

Given that this is for your wife's car and you don't need axle snapping power, I would suggest a flat top piston and changing to D3VE heads. This should give you approx 9:1 compression. Stock replacement pistons with a ~12cc dish will give you approx 10:1 with the 72cc heads you have. That would probably be okay with premium fuel, but it doesn't sound like you need to push the compression for your power goals.

Pair the 9:1 piston/heads with a dual pattern cam that has 204-214 @.050 intake duration and you should have a nice running engine that will still make more power than she needs.

I believe Summit Racing sells a rebuilt kit with the flat top TRW pistons and everything else you need except the cam and lifters for about $600.00. You might want to check that out.

429 Pistons I'm familiar with are as follows:

Kieth Black: KB368 (hyper w/flat top), 1161 (cast w/dish)
Clevitte 224-1869 (cast w/dish)
TRW: L2366F (forged)
JE: 3977 (forged)
CP PISTONS: F6-CP (forged)
ROSS: 78473 (forged)

[racedraper]

well im getting Kieth black hyper soethig 909's but I cant use my stock rods cause they are pressed in pins. so Im in the market for floating ones if anyone has them.

[CarsByCarl]

Originally Posted by racedraper

well im getting Kieth black hyper soethig 909's but I cant use my stock rods cause they are pressed in pins. so Im in the market for floating ones if anyone has them.

You probably don't need to float the rods. The piston/pin clearance is the same in a press fit or float, the only difference is in the rod/pin clearance. Just press fit the pins in the rods as usual and leave the retaining clips out.

As for the strength of hyper pistons, you shouldn't have an issue. Ford uses them in the 460 crate engine with 545lb/ft and 550hp at 6250rpm. I use hyper pistons in my 514 Workhorse crate engine that makes 453hp and 581lb/ft and have no problems. If you follow the KB clearance and ring gap guidelines closely you should have no problems.

That being said, I think regular cast pistons would be fine for your application and a little less expensive too. I've personaly run them in 429's set up the way I outlined above for 50,000+ miles of street/strip style driving and never had a problem.