Here is the info on some of the 4-bolt blocks I have for sale. All are in great condition or better.

400 YC code, K207 date, 9790071 casting number, +.030, O-ringed, ran in a competition 69 GTO. These were factory caps professionally mated to this block. I have another such block done up the same way, which I ran with alcohol injection as a 406 cu in engine, with a RA5 top end. I have pics if you want to see.

428 SR81579 code, D247 date, 9792968 casting number, std bore, never used.

428 WG code, K177 date, 9792968 casting number, standard bore, not previously listed, $1500.

455 YG code, D071 date, 485428 casting number, +.040 (clean), not a 1970 which I originally thought. Old age, bad memory.

455 SR84469 code, L203 date, 485428 casting number, +.030.

I also have a 1965 421 which is +.090. Clean bore. I ran this block with a 63 SD 421 crank, 455SD rods, venolia pistons, with a set of RAM AIR 5 heads on top. Block has very few passes on it.

I have 100's of heads, blocks, and cranks. Thanks to everyone for inquiries. Email me at pontiaclarry@sbcglobal.net. MAKE OFFERS!!!!!!!!!