So im using a 1973 350 truck block with my 305's TBI setup and i have no idea which knock sensor to use? also are there any heads that i can get for cheap and build that will work with this setup that are better than my 305 heads or the old 73 truck heads?

 

I'd read the sticky on the 350 swap, I guess you could get away w/ the stock sensor & see how it runs. Especially if your not running high compression ratios.
I guess a good set of cheap heads would be some vortecs, but they require a vortec intake & gasket set. You can get a vortec 4bbl. intake very reasonably & use a tbi adaptor. Those heads flow better then any stock chevy heads & almost as good as the LT1 heads from the 90s.
305 heads on a 350 block will boast your comp. ratio.

 

You need a 350 knock sensor. You'll also need 350 injectors, a 350 TBI prom chip (from a caprice or truck). You might also need a VATS bypass module - your VATS sends a 30Hz signal to the ECM, a 350 ECM might be looking for another frequency (there were 2 signals, 30 Hz and 50 Hz) - this is of course if you use a 1989 or later 350 TBI prom chip, pre-1989 no VATS, so no VATS issue.

 

I understand that it needs to be a 350 knock sensor lol, but there are different 350 knock sensors correct? sorry for the confusion.

 

Hope this helps https://www.thirdgen.org/forums/tbi/...ck-sensor.html