i have been running a b20f in my 66 wagon for 6 mo.the b20f is the most available and cheapest since it came in the sedans.if you are going to make an engine change you have to disassemble the b20 and bring it to new specs.plane the block at least to zero piston height best piston .005 up.you must install valve seats or the valves will recede into the head in short order.a good cam and springs.i installed an isky cam dual springs and their smaller lifters and push rods.all items they have been selling since the sixties.with the dual outlet b20 ex manifold the engine pulls strong to over 5000 rpm.i ran a generator until it died then installed an alternator from a 240 with a slight mod to the lower bolt flange(i shorten it with a hack saw to align the belt). the 140 alt uses a voltage regulator which is unnecessary today.also i like the stainless steel valves because they are so slim and flow well with bronze guides.i planed the b20f head .040 to increase the compression ratio to a better spec.with alot of money spent on a rebuilt engine a new radiator is essential.once the new engine is up and running a 1 inch front sway bar from addco transformes the handling.