I'd try to get a mid 80's truck block, most trucks had 4 bolt mains(they also had 305's make sure you get a 350). The solid lifter vs. Hyd. lifter also depends on your budget, solid is alot cheaper . I'm going with a 350 bored .030 over with 6 in. rods and a 3.480 stroke crank and a flat tappet cam with soldi lifters with my junkyard rebuild. Heads are better to get aftermarket if you want power (vortecs are nice but req. the vortec intake and such), then a good intake and 4 brl. carb and you should be good to go. Also the iron block is fine, but I'd get Aluminum heads.