[Goatracer1]

Does anyone still sell low compression 389 pistons? It probably will need +.030 pistons. I can find lots of reg. pistons. I really don't wand to bore a cherry 389 out enough to use 400 standard pistons.

[tom s]

Maybe EGGE?Tom

[MarkS57]

What year 389? If you can make a std work, these have been on ebay F O R E V E R. Maybe make an offer, still probably less than 1/2 of a Ross custom or 2/3 of a DSS

https://www.ebay.com/itm/25491660366...Bk9SR-zt9PWvYQ

[Jay S]

DSS has them in 4.08” and 4.1” bore with a dish. No .030” over that I am aware of.

[Goatracer1]

What is DSS full name.

[77 TRASHCAN]

Paul K is a dealer for Autotec/Racetec pistons. He can get what ever you want!!!

[Jay S]

DSSracing


https://dssracing.com/Pontiac-piston...55-stroker.htm

[geeteeohguy]

I put together a .030 '65 389 about 12-15 years ago using Ross forged dished pistons. Still running great on 87-89 octane. The cost back then was about $500, but IMO, worth it not to hog the block out to the max.

[lust4speed]

Just received a set of Ross dished pistons through Butler for a 389 build. Pistons were ordered with custom bore size, dish, and compression height. Went only large enough to clean up the bores and specs to arrive at the desired compression and zero deck height with the 72cc Edelbrock heads.

[tom s]

I have been very happy with the Autotecs through Paul K.Will be ordering another set soon.Tom

[Goatracer1]

Thanks for the suggestions but I don't need forged pistons. It's my wife's driver and I can't justify $700 for pistons.

[MatthewKlein]

Originally Posted by Goatracer1

Does anyone still sell low compression 389 pistons? It probably will need +.030 pistons. I can find lots of reg. pistons. I really don't wand to bore a cherry 389 out enough to use 400 standard pistons.

What compression ratio are you shooting for? What cylinder heads are you using?

[MatthewKlein]

Originally Posted by Goatracer1

Thanks for the suggestions but I don't need forged pistons. It's my wife's driver and I can't justify $700 for pistons.

STD $433
https://www.summitracing.com/parts/u...d/make/pontiac

.030 $339
https://www.summitracing.com/parts/u...0/make/pontiac

[25stevem]

To who ever may use these Silvolite pistons that they offer for any CID Pontiac be sure to carefully check the oil drain back grooves in the rear of the oil ring rail.

There has been casting flash known to be left in them, which is not a good thing not only for having the needed drainage, but to also not have that flash come loose once the motor is running.

[Goatracer1]

I'm using the original 1962 538177 cylinder heads. I'm looking for a compression ratio that will allow me to use 89 or less octane pump gas.

[Goatracer1]

The Summit pistons are flat top and don't appear to be low compression.

[tom s]

Again,try Egge.Tom

[Goatracer1]

Egge's piston sets are almost $800 and are not low compression. But thanks for the suggestion.

[77 TRASHCAN]

Phone number for Silvolite pistons 775-882-7790 tech@UEMpistons.com

Phone for Mahle pistons 888-255-1942

[b-man]

Cut a very shallow dish in the Silvolite pistons, maybe something like 3” diameter by .060” deep (7ccs). Do some work to the chambers to get a little more volume.

Between the two you should be able to gain 10 to 12ccs I would think without compromising the strength of the pistons or hitting water while doing the chambers.

With a 77cc head (after removing 5ccs) and a 7cc piston dish on a 4.093” bore at zero deck along with a Butler .045” head gasket you’d be looking at 9.54:1 compression.

That should be manageable on 89 octane with proper cam selection.