looking for the closest to original pistons for 71 440 Six pack

[6PK2GOBEE]

so, why a factory 10.5:1 piston? is this a 100% restoration only? does it make any difference about what kind of gasoline will be used?

I’m running the TRW forged L2355F pistons that have the 4 valve reliefs in them with 906 heads and the compression ratio comes in at 9:7-1 normally. But with the block and heads resurfaced it’s actual CR is more like 10 or 10:1-1 using the stock Fel Pro steel head gasket.
The pistons are level with the deck. The weight is close to the factory cast pistons.

 

[Babyblue66]

2355 work well and a fair price

 

[Randy Wilson]

IVE READ THAT THE 2355 PISTON WAS MODELED AFTER THE 71 6PK PISTON. I ONCE TORE DOWN A 69 6 PK MOTOR THAT HAD SPUN A ROD- IT WAS A 71K MOTOR THAT HAD NEVER BEEN TORE APART. THE FACTORY PISTONS WERE PROBABLR .002 DOWN IN THE HOLE. I AGREE WITH FM3 DART. IN ADDITION, MY FRIENDS 71 ROADRUNNER FACTORY 6PK WITH ORIGINAL MOTOR, NEVER APART HAS 906 HEADS- DON'T KNOW IF THATS AN EARLY BUILD THING OR NOT

 

[6PK2GOBEE]

The 69 A12 engines were the same as 440 magnum of the same year with some extra attention paid to the internals. Same piston 10:1-1 CR flat top, no valve recesses.
In ‘70 they went to the wide beam rods and 10.5:1 CR pistons with the 4 valve recesses on ALL 440 6bbl & 4bbl magnum engines. Advertised CR dropped to 10:2-1 for ‘71, otherwise same as ‘70.

 

[Gunner1]

I can tell you that mine with 7cc valve relief, .017 down the hole, .039 felpro 80cc Stealth CNC heads, Isky 292 mega cam [email protected] and a holly 750. I can run great on 12 deg initial and 24 more centrifuAl on 91. If I wanna lead foot it I take 2 degrees out. Otherwise it has a very light ping Right at the top of second.

 

[BSB67]

I can tell you that mine with 7cc valve relief, .017 down the hole, .039 felpro 80cc Stealth CNC heads, Isky 292 mega cam [email protected] and a holly 750. I can run great on 12 deg initial and 24 more centrifuAl on 91. If I wanna lead foot it I take 2 degrees out. Otherwise it has a very light ping Right at the top of second.

Sounds like a solid but simple combo. I bet it runs well.

 

[Gunner1]

Sounds like a solid but simple combo. I bet it runs well.

I still want to dyno it and do some jetting and timing under load. But i'm pretty satisfied so far.