All,
My old 305 was showing low oil pressure after 150k miles so I had the engine swapped out with a Jasper Rebuilt 350 Tuned Port engine. Everything swapped out fine. I did not change out the injectors. They were a hold over from the 305. Should the injectors be changed out do to the slightly larger engine? I did not do anything to the computer either.
V/R
Kerry

 

I’d suspect it’s running lean. A spark plug read or wideband or watching fuel trims would tell you. You might consider a proper tune and 22#hr injectors .

 

I'd look at your BLM's on a scan tool and I agree w/TPerf that you'll see that it's trending to correct for a lean AF ratio. If I saw that, I'd swap the injectors, skip the tune and go burn some rubber.

Cheap skate's trick: Buick 3800 series II normally aspirated engines use the right sized injector for the 350 TPI. I got mine from a junk yard for $6 each.

 

Agree with Tuned Performance....a 350 engine should use 22lb injectors

 

Or bump up the fuel pressure