Basic rebuild: What 306 piston with bigger valve reliefs and gives more compression?

get probe pistons.....forged and really nice quality

More compression is usually done with deck clearance and head milling or smaller chambers. If you are using a basic small block Ford style flattop, there is not much to be gained in compression between any that I have seen.

There are dished ones to lower compression for blowers.

If you want a compression increase with pistons, you are looking at domed pistons, which will get you up there quickly.

If you look through a piston catalog, such as the TRW/Sealed Power, you will see a lot of pistons, but the compression distance is nearly identical.

Careful decking and head milling are the best bets.

PROBE 302 - 3.000 Stroke - 5.090 Rod - 1.600 C/H - .912 x 2.500 - 113 Gram Pin

Bore Weight 58cc 61cc 64cc 68cc Part #
4.000 480 11.17 10.70 10.27 9.75 10466-Std
4.030 485 11.30 10.82 10.38 9.86 10466-030
4.040 490 11.34 10.86 10.42 9.90 10466-040

Dome Volume 8.0cc

If you need some let me know
Ring Grooves 1/16 1/16 3/16

Looking for opinions on the Wiseco pistons, specifically their part number PT012H3...Considering these for a 302 short block for a buddy of mine, I am just wanting to see if anyone has experience with them.

Shoot me a message at Rick91GT@suscom.net and I'll see what I can do.

I know of a few pistons that would do it with a stock rod and a stock crank.

How's this sound...

Bore Size: 4.000
Gasket Bore: 4.100
Piston Top Land Dia: 3.965
Stroke: 3.000
Connecting Rod Length 5.090
Compression Height: 1.600
Deck Height: 8.200
Ring to Top of Piston 0.250
Gasket Thickness: 0.040
Valve Notches Volume: 0.00
Dome Volume: 8.00
Volume Head: 58.00
-------------------------------------
:COMPRESSION RATIO: 11.027
-------------------------------------



calculation variables:

Piston to Deck: 0.010
Crank Throw: 1.500
Vol. Above Top Ring: 0.90 cc
Piston to Dec Vol.: 2.06 cc
Gasket Volume: 8.65 cc
Volume Clearance: 61.61 cc
Cylinder Volume: 617.78 cc
CID: 301.474


or if you go with a .050" thick headgasket which ROL makes.

Bore Size: 4.000
Gasket Bore: 4.100
Piston Top Land Dia: 3.965
Stroke: 3.000
Connecting Rod Length 5.090
Compression Height: 1.600
Deck Height: 8.200
Ring to Top of Piston 0.250
Gasket Thickness: 0.050
Valve Notches Volume: 0.00
Dome Volume: 8.00
Volume Head: 58.00
-------------------------------------
:COMPRESSION RATIO: 10.687
-------------------------------------



calculation variables:

Piston to Deck: 0.010
Crank Throw: 1.500
Vol. Above Top Ring: 0.90 cc
Piston to Dec Vol.: 2.06 cc
Gasket Volume: 10.82 cc
Volume Clearance: 63.77 cc
Cylinder Volume: 617.78 cc
CID: 301.474

I can go 4.03" bore also