302 Replacement Pistons

[Z28Project]

I'm looking at doing a 302 +.030 rebuild and going to buy a set of pistons.  There was a good thread on this a few years ago discussing the various pistons available, but it looks like piston choices have really narrowed in the last few years.  It looks like you can change rod lengths and use 350 pistons, which have more choices, but if I stay with a 5.7" rod, the choices I'm seeing are hypereutectic or the JE/SRP forged.

I don't really want to go hypereutectic, and I have no problem with the JE/SRP piston, I'm just wondering what others have done (if anybody has done any recent rebuilds), or if I'm missing something in my searches.

JE offers the pistons and rings along with some nice looking MLS head gaskets in various thicknesses (.027, .030, .039, .051").

One goal I have is to keep the compression UP!  11.0:1 at least.

I plan to run the stock 30-30 cam.

Thanks for any info/opinions.

John

[jdv69z]

I thought to go to a 350, you have to change the crank, and the rods stay the same.

[Z28Project]

That would give you a 350 CI engine.  In some of the posts I was reading they indicated you could change the rod length to compensate for the different wrist pin location of the 350 piston, use 350 pistons (more choices), and still end up at 302 CI.

[jdv69z]

New one on me!   

[1968 Z28]

If you are looking for an exact replacement piston, the JE #123567 is the exact 302 factory replacement.  It is not a SRP piston but is the NHRA approved replacement piston for the 302ci engine.  It will give you the stock compression ratio of 11.1 and it has the original size ring grooves.

[Z28Project]

Thanks!  Let me see what I can find out about those.

John

[1968 Z28]

Here is a link to the JE web site......http://www.jepistons.com/Catalogs/Automotive/NHRA.aspx

[janobyte]

JE are good pistons. Maybe lighter then stock, a plus with theses engines. Stock are heavy. Rod failure secondary to " yanking" them back down during high revs. All in all stout rods, after stress relief, good forged cranks. 

[Z28Project]

Thanks for the link Jerry.  I was having trouble finding them on their site.  From your link I see I needed to click on NHRA.

Yes, everything I've read sounds like JE makes good stuff.  I think it will come down to either the 123567 or the JE/SRD 202890.

Thanks,  John

[X33RS]

I just finished my 302 build and used the JE pistons.  Excellent pistons.  I noticed the dome configuration slightly different as well as the quench area when compared to my NOS DZ pistons but nothing that affects much of anything.

My compression with the pistons .005 in the hole, .039 gasket and 62cc heads came in exactly 11:1  They are slightly lighter than the stock piston.

[Z28Project]

Thanks for the info X33RS, especially the numbers!

Did you use the SRP series?

[X33RS]

Yup,  SRP series 202890 part number full floating with a 1/16 ring package and went with total seal rings.

[Z28Project]

Great.  Exactly what I was looking at!

Thanks,  John

[asm69]

X33RS, why didn't you use pressed pins instead of full floating pins? I believe Jerry McNeish uses pressed pins for the safety issue.

[X33RS]

There were a few reasons, one of which was to stay true to form.    I've used floating pistons in several builds without issues over the years so no real concern for me.