Can someone give me advice on pistons?

[TomSchichtel]

My block, heads, crank, and rods are all at the machine shop. The machinist needs pistons soon and he recommends forged probe pistons over forged Kieth black pistons. So I'm looking at 70 over probe pistons and here are some of the option differences that I don't know about:

Compression Distance: 1.460in or 1.664in

Flat Top with two valve reliefs or Dish with two valve reliefs

Piston head volume: +5.50cc or +17.50cc or +14.50cc

Those are all the listed differences. About my car and what I'm looking for: I'm running 3.23's, non overdrive 883, 360, 73 duster. I'm looking for a hot streetable motor.

 

[70aarcuda]

stock stroke 360 uses the 1.664 compression height pistons

a 4 inch stroke 360 will use the 1.460 compression height.

 

[Coronet 500]

The best way to understand and decide piston choice is with compression height first.

Block height is 9.60" minus rod 6.123"= 3.48"

Take 3.48" minus 1/2 stroke 1.79"= 1.69"

This is the distance fron pin center to top of block called C.H. and how much you have to work with. Minus your 1.664" = .026" below deck and low compression.
A different piston with 1.675" C.H. = .015" below deck and higher compression.
The 1.40ish sizes are for stroker cranks.
The pluses and minuses are options for differnt compression ratios once you have decided C.H.
I would always get deep two valve notches for future big cams to fit.

 

[273]

Depends on what crank, heads, cam and fuel your gonna use

 

[rumblefish360]

To break it down in simple terms and dependent on the head cc's and material, iron or aluminum, you want a streetable pump has freiny ratio with a med. size cam. If you know the cam your going to use, please post the specs.

9.5-1 max,iron head.
10.5-1 max, aluminum head

Large cams bleed of se compression. So if a big cam is going to be used, you can start adding some more compression. The same will apply if the cam is small, oh in reverse. You'll need less compression.

Actual manufacturer of the piston doesn't really matter much at all except to some people that do the actual work. Your machinist may recommend the Probe brand over the KB for a reason. Be it his preferance or known quality issues or what ever.

Get with your machinist to tall about what your doing a d where you want to end up.