Will these pistons work with 781 open chamber 118cc heads with 2.19/1.88 valves? I was going to use the L2465F pistons but have read too many stories about p/v problems. My block is .060 over and not zero decked. Will be using stock 6.135 rods. Have not picked my cam yet. Looking to build for around 500-550 hp 468ci. Would like to get 9.5-10 cr.

those are cast pistons, you sure you want to run cast pistons in a 550 HP BBC?

I've used the 2465s a couple times with no issues. They won't work with CC heads without mods but you have OC. did you read that stuff about clearance problems here? Got any links?

I ran the 581s and 049 heads that were cut .030 and had .120 clearance with the block being 0 decked, It is also a 468, it is still running in my old Chevelle. actual compression was 10.98, my best was 11.19 @ 119 at this altitude and ran 10:89 in Boise last year. it has a solid Crane cam # 113311 I believe .618 .636 lift, Truck rods, stock crank, heads were ported and had 2.19/1.88 in them. I ran this engine myself for 4 years, I did bearing changes every year just to inspect everything. we calculated the HP at the rear wheels to be 396, the pistons were coated and held up and wore great. just my combo
Jerry

I would like to run a forged piston but can't spend $500 on them right now. How about the Probe P2465F piston? Would these work with my combo? They supposedly have larger valve reliefs in them for better clearances. Maybe what I read about p/v clearance problems was with the closed chamber heads and not the open chamber ones....hummmm.

Sure you can when you figure in what replacing everything will cost you when one let's go up top once the dreaded, "More power, Scottie" bug bite's you AND it WILL before it's over!

Heck, I went from a dingle-berry hone/Krylon 454 to a 475, (.100" overbore), to a 496 on paper and when I put my 496 together, I installed .020" thick shims instead of the kit's .039" blue jobbers to up my CR. like 0.3 a point, from 9.5 to about 9.8!

Plus two intakes and three cams!

pdq67

there's no difference in piston to valve (p/v) clearance between closed and open chamber heads. there can be interference between the piston and the head if they're mis-matched. See the BB info thread at the top of the Engine section for detail on this.