Just figured this might be helpful as general information to anyone swapping in a 350 like so many of us have. While I am reeiterating a lot, at least all the info is in one place. Hope it helps someone.

To swap in a 350 in place of your tired 305 you'll need to:

1) Replace the knock sensor and knock filter with 350 units
2) Install larger injectors (55-65 lb/hr)
3) Install fuel-pressure-regulator and gauge (to adjust richness)
4) Stick with a cam with around (.440 / .450) lift if you're buying aftermarket, or a LT1 cam if you find one. Otherwise the computer might not like what it reads.
5) Reprogramming the EPROM is the best way to gain maximum efficiency and power
6) Consider your cooling system. The stock fan kicks on at 230 degrees or higher - DEFINITELY LOWER IT. A lower temp thermostat and larger radiator are always helpful too.
7) Free up your motor - open element air cleaners, deleted a/c, and other amenities are a really good way of eliminating extra hardware (if you dont want the stuff in the first place) while making your engine compartment look less like an electrician's nightmare.

Buying a Holley 670 TBI? Welcome to hell. While the holley unit performs flawlessly, they initially released the product with 85 lb/hr injectors (yea, 85). Two years ago, they realized they goofed and recalled the bodies, installing 65 lb/hr injectors instead. If you're banging your head against the wall fighting a rich running motor, THAT may be why. Call holley and yell at their technicians until they promise to send you the right injectors free. The guy i talked to told me my fuel return line was plugged (wrongo) and that just adjusting the fuel pressure would fix it (even tho below 9psi poor atomization becomes a problem - can u say drip drip?). Dont let them talk you out of what you deserve - you paid what - 350$ for it?

In general, a 350 swap is an easy accomplishment after the first time - so don't give up if you run into troubles. I spent my first summer with the car hunting problem after problem after problem and just recently have i begun to win the war. Also, in my opinion, while a cam does make good hp, theres much to be said for a good porting job and a stout bottom end. Who cares if the other guy has 400hp if he can only make it at 6500rpm and he's never balanced his bottom end?


Tyguy

 

good info Who cares if the other guy has 400hp if he can only make it at 6500rpm and he's never balanced his bottom end?
this is so true