1971 Duster 360/727

Hey! Sorry for the delay in response.

"Zero deck height" is when the piston is exactly the same height at the top of the block, where the head sits. Those pistons that I showed are a flat top that have been rasied up in there height a little bit more than a stock piston. For more compression.

Placing the piston at a zero deck height would more than likely require some machine work to the deck.

No head work would be needed. Placing the piston this high allows the compression ratio to be raised even further. In most cases, it also allows a good quench area. BUT! The compression ratio can get to high IF there is not a good enough octane available and/or the cam is to small.

Placing the piston at zero deck may not be a good move for your planned engine set up. I normally do this to my engines that are planned to be a bit more energetic.

On the cylinder head valves, a 2.02 - 1.60 is what your after. I have never seen a small block with an exhaust valve bigger than 1.65.

Adjustable rockers on a performance engine is an excellent idea. You can order custom length pushrods later. Getting the rocker geometry is a critical part of not just engine performance but also long life for the valve & guides.

On getting parts from e-bay, I tend to shy away since if it is not brand new, I could be purchasing other people's junk.

A Good adjustable rocker arm could come from Hughesengines, Comp Cams, crane Cams, Harland sharp, just to name a few. Crane has mechanical rockers as well as roller rockers.

Edit! Thanks Trebor! Your mention of a cup or ball adjuster is something I forgot. The pushrod will have to be made to match the adjuster. Which is no big deal.