I wanted to keep my HP-273 in my 66 GT so I bored it .030, used Egge's 10.5:1
pistons (which are @ 9.67 with some head shaving and a .025 thick Mopar gasket) The Egge's are 68 grams lighter than the stockers so the assembly got balanced.
I used a Isky E-4 solid lifter cam ( 260/.425/108 deg) which is a bit bigger than stock specs driven by a Cloyes street double roller.I also installed a MP windage tray. I had R&J performance build my heads. They milled them .030 to save compression lost by the thicker head gaskets. They replaced all the valves and added 340 springs. They also installed bronze guides and did a port match and mild port job along with a polish to the chambers. I will use the stock Prestolite dual point distributor and the stock cast intake ind the original AFB carb. I am presently working out the bugs with pushrod length as I assemble and paint the pulleys and brackets. I was hoping to get it assembled and drivable by Memorial day but I don't think I'll make it. I don't want to rush it. This has been a fun build for me. I have overhauled engines before but I have never done one to this extent before. Thanks for this thread. toolmanmike