Quote:
Originally Posted by 1969GPSJ
I am betting you are right. My gut says so, but I have no experience to confirm.
My battered old '69 shop manual (printed in 1971) implies they did - on Page 6-40 it even shows a picture of all the V8 pistons, with it showing a plain flat top with valve reliefs for the 428 piston top. I think they mixed up the 400 picture (it has the dish in the picture) and the 428. The only 428s I have had apart were the '67 670 headed big valve 4 bolt YH coded 428, the '68 375 HP engine, the '69 360 hp small valve engine (also with a YH stamp on the block), and the '69 370 HP Big valve engine. All of them have the pretty substantial dish in the piston. I just have never disassembled a previously unmolested 428 HO.
Supposedly the 428HO had a quarter point more compression (to 10.75:1) to go with the 068 cam - and those 2 things with the long branch manifolds were apparently what made for the 20 HP difference between the 370 and 390 HP engines.
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Ok so spill the beans, whats your plans on moving forward. ?