i have a 67 430 and a 72 455. i plan to build the 455 but have been told the 430 heads might do me better. my over all goal is 550 horses on pump gas if can get more hp better. i would like as many sugestions as possible. the motor is going in a 37 chevy pick up w/o fenders it will have a winters quick change and i want to lift the front end off the ground.
Perhaps they were thinking of the 67 iron exhaust manifolds being superior? Perhaps they were referring to the relative stock chamber size?
No i'm pretty sure the 67 heads have bigger ports than the later model 455 heads have your 430 heads converted to stage one valves with some nice port work and a good shortblock buildup and you'll make 550 hp easy.
I believe there are two different 430 heads, regular port and tall port. Someone did post the casting numbers of which is what. I have a set of 430 tall port heads sitting at the house. Someone with more experience with these heads should be able to help you out.
http://www.atlantabuick.com/CastingNumbers.htm 67 casting #s for 430 heads 1372963 1382983 1382985 1382986 the base heads from 67-70 all had 69cc chambers. your 72 should have 71cc chambers unless you somehow got ahold of a Stage block ... and didn't know it. :laugh: the big thing is that the stock 67 heads (and most of the 68 casting #s) actually have better flowing ports. http://www.buickperformance.com/Exhcompare.htm the 67 drivers side exhaust manifold has a flow advantage over all other year production manifolds so you'll also want to use that. http://mywebpages.comcast.net/jholthenrichs/knowledge.htm#rocker arms the 430s have a higher rocker ratio (1.59) than the 455s (1.55) so you'll get free extra valve lift for a given cam. warnings: oiling: the 430 oils through the shaft vs the 455 oiling through the lifters. rocker arms: the 430 uses a 3/8" socket vs the 455s 5/16" intake manifold bolts: the 430 uses 3/8" vs 7/16" on the 455 http://www.taperformance.com/faq's.htm Q "I have a 455 and would like to use `69 and earlier 430 (400) heads, what do I need to do?" A The 455 engines oiled the rocker assemblies through the pushrods, where as the `69 and earlier heads oiled the rockers by use of passages through the block and into the heads eventually entering a hollow rocker shaft and weeping into the rockers through passages. The 455 engines only have the oil passage on the drivers side (LH), so oiling the rockers MUST be done through the pushrods. The oil passage on the driver's side of the 455 block must be tapped and plugged with a flush pipe plug, no modifications are necessary for the heads. If using 455 rocker assemblies, use the 455 lifters and pushrods. If using the 430 (400) rockers use the 455 lifters and hybrid pushrods that incorporate the 455 ball end at the lifter end and a 430 (400) ball end on the rocker end. Do NOT use 455 pushrods with the 430 (400) rockers, the ball end is too small and will wear and eventually break through the rocker pushrod cup. be sure to read all of these pages and you should probably search for more info online. also, TA has experience with this kind of a swap so you could call them for more info.
