[RallyBob]

You can't use Opel valve seals! The Opel valves are 9 mm, Chevy valves are 11/32. You need new guides, new valves, new seals, you SHOULD install exhaust seats, and you'll need new springs, retainers, and valve locks. Otherwise it won't work out.

If you are installing larger valves, you have to cut the seats before you can unshroud the chamber. I use old dummy valves installed in the head to prevent seat or valve damage while grinding. Cc'ing is overrated. Not necessary on a street engine. Other than for calculating true compression ratio, it serves no purpose for 95% of the enthusiasts out there.

I never built the blower engine. Too many distractions! I built the 2.4 shortblock, ran it in naturally aspirated form for a while, then tore it down to inspect for wear ( I always do this when building new concept engines). I had the block re-honed, and wrapped it in plastic,where it sits to this day. Some day I'll built the blower intake and put it together. I'm thinking it would go great in my Kadett wagon. Imagine 250+ hp in a 2000 lb grandma car?

I think you'd better invest in longer connecting rods with that 305 Chevy pistoned engine you're thinking about. The piston will be about .210" below deck! Probably about 5.5:1 compression or so! Maybe try a 5.2" Ford 2.3 Pinto rod. Narrow the rod by .0065" per side (.013" total) to fit the Opel crank, and now the piston will be only about .050" below deck.

Bob