Dodge 318 pistons are a close match at 3.910 standard bore (ends up as .035" over for the Pontiac 350).
CD is 1.700, pin diameter .981 for the Pontiac 350. CD is 1.720, pin diameter .985 for the Dodge 318 (L3013F). CD is 1.739, pin diameter .985 for the Dodge 318 (L2406F).
Measure your deck height and CD (compression distance) with your stock pistons. You may be able to have a zero deck without surfacing the block. The pin end of the rods will need to be opened up to the Dodge pin size. Both pistons are flat tops.
Real cheap if you don't need forged: Ebay item #180066391742
There aren't any! I looked everywhere a year and a half ago when I was rebuilding my 350. Found some cast .040 over pistons but nothing forged. I even called Sealed Power and a couple other piston manufacturers.
Somewhere I have a copy of that article describing using the Mopar pistons in the 350.
I've got a set of 7 .040 over cast pistons if you're interested.
-=>Lee<=- Due to budget constraints the "light at the end of the tunnel" has been turned off!
You could also use .040" over Olds 400 pistons. These are nearly the same dimensions as a 350 Pontiac piston at .035" over. You do not need to have the dish rim machined off to reach the correct compression height! Leaving it on will actually improve your resistance to detonation and will have the same effect as zero decking the block woithout increasing the compression. However, you will need to have the Pontiac valve relifs machined in. These pistons have the same wrist pin as the Pontiac.
I have a set of these pistons that I was going to build into a high-performance 350 project that I haven't gotten around to yet. The modifications are quite easy for a competent shop or machinist to make.
The compression height is too large, but no problem to cut them down to fit (1.80 SBC Vs. 1.70 Poncho 350). The valve reliefs will be wrong, but no problem to add the right ones. The pin diameter is .927, so you'll have to bush your Pontiac rods to use them.
In almost every way you are going to be out about the same amount of money. My plan was to use the Olds poistons and "soft head" the tops with corner reliefs for the valves. For most rebulds, a set of purpose-made pistons would make the most sense.
Check with Ace on the PY board. Performance something, believe he is in CA. He has stuff for 350's He was telling me you need to check the head gaskets on 350's as well, plain rebuild types can drop your compression a good bit.
Wanting a Custom fit in an off the rack world.
I don't have time for a job, I just need the money.
I know I should look this up myself...but I'm being lazy.
From a structural standpoint, what's the difference between forged and cast? If you don't plan on hitting it with Nitrous or have severe detonation issues do they make that much of a difference?
I know I should look this up myself...but I'm being lazy.
From a structural standpoint, what's the difference between forged and cast? If you don't plan on hitting it with Nitrous or have severe detonation issues do they make that much of a difference?
From the question I'm assuming you didn't take metalurgy class. And since you probably don't want a trip down metalurgy lane, here's an analogy for non metal experts; You could make your furniture out of pine(cast) or walnut(forged). The pine furniture is fine but when someone decides to 'dance on the table' you will wish you had walnut.