would have to disagree with you on the cost to build a mild street pontiac & most others on here who have done it probably would too.
yes parts are cheaper but machine work is machine work & costs the same for most motors.
i didnt mean aluminum heads & stroker kits or custom pistons etc, just a good mild street engine with common parts.
you can build a 350 hp pontiac 400 with stock crank & even rods at that power level but the RPM forged rods arent much more than rebuilding stock rods...
a good cam selected with a very easy to reach 9-9.5:1 comp & you're easily at that HP with more TQ than a SBC. & the stock mounts, fuel lines & wires hook right up.
im aware there are a lot of haters on the 301 & 301t, but have you ever owned one that ran right?
they were within 10 HP of a 78-79 W72 400 rated at 220hp, the 400 had more tq & that meant faster off the line or seat of pants feel, but at a 30-40+mph roll they will hang right with the 400s.
i own an 81 301t & its 99% stock, runs 14.8 in the 1/4 not full throttle on hard old street tires, not "fast" by any means but almost a second faster than a stock W72 400 times.
& there are lots of guys running them into the 13's & a few in the mid 12's using stock heads, turbo, carb etc in a NHRA class. so they arent as bad as the rep they got over the years.
keeping the 301 was just a suggestion mainly for resale value depending on what you plan to do with the car. if youre keeping it for awhile, do what you want to it, if it will get sold, staying pontiac will most likely pull more money.
bang for the buck? pontiac all the way!
just my thoughts.