Haven't been able to find casting no yet but the no stamped on the block below the alternator is 1m1226 with a stamping below that of IVP. Based on the small block Chevy engine code the 1m stands for a 1969 350 - 255hp with 9.1 compression. My compression readings are 4@135, 2@138 and 2@140 which coincides with the published CR.

Head stamp is 83417369, Hencho in Mexico. I believe these were used with gm crate engines and have 1.94" intakes and 1.50" exhaust.

I really have no idea what the cam is other than its aftermarket and has a moderate lope at idle.

Hope this helps and thanks for the suggestions on intakes.