I just completed a 302 as we speak.I used Chevy V-8 1.94 intakes and 1.60 exhaust valves,Manley hi po street valves,springs with a damper,again V-8 item.Comp cams makes a lower spring cup that fits perfect and gives a 1.700 installed spring height,perfect.The small block valves have a slightly shorter stem,ya need to correct the rocker arm geometry,easy to do.I got a cam ground of my own specifications,I highly recomend Colt Cams in BC Canada.My cam is 215 degrees duration at .050 lift,lift at the valve is .430.Remember this,the actual GMC rocker arm ratio measured by me is 1.4 not 1.5 listed by all cam makers.So, all the cams you see are short on actual valve lift by about .035 and short on duration by a few degrees.
I'm running an actual 9.3 compression ratio,Venolia pistons,I sent them a mold of the combustion chamber to design the piston.Using 1/16 compression rings,3/16 oil rings.I measured the stock 302 head combustion chambers at 121 cc's,had the head milled .040 to get the chambers to 112 cc's to keep a small 25 cc pistom dome.The pistons are installed at zero deck clearance.The rod small ends were rebushed for Chevy big block V-8 wrist pins so I wouldn't have to have custom pins made.
I searched around quite awhile to find Clevite 77 bearings,the mains have been out of production for 20 years.I didn't want to use the currently available Federal Mogul made in Mexico bearings.
Got a 390 Holley 4 bbl on a Patrick's intake and a home made set of short tube tri-y headers.
I modified the the oil pump pick up tube by using a larger diameter tube from a V-8 with a home made pick up enclosure and screen.And of course the full flow oil filter.
Should make 230 HP at 4500 rpm.
302 in basement More 302
