New guy with questions.. 462 fuel issues.
Hi, I'm new here, I think I may have registered in the past but could not find my login. Anyhow, my good friend and neighbor has a 1969 Pontiac GTO. He wanted one his entire life and finally bought one. He got a little screwed. The "dealer" told him the car was restored with an original GTO engine, not numbers matching and not the original motor. Well it wasn't, it was a smog era 400 from 1975 (IIRC) that made like 185 hp. Well he loves the car so a few years ago he bought a pro built 462 with Kaufmann aluminum heads from a guy named Jeff in Michigan (I think). The dyno info he got with the 462 says it makes 605 HP. I helped him put it in. We got it running, but it was never quite right, hard starting and stalling issues, it never idled very well. This past weekend I went to help him get her woke up for spring and she was really running rough. He put a 750 Holley on it last year with a Earls fuel line kit with a filter and pressure gauge. Well, as we were trying to get it to idle I noticed he only had about 3 lbs. of fuel pressure. It was like spitting raw fuel out of the tailpipes. He told me he had replaced the pump with a reproduction Ram Air pump from one of the restoration companies that specialize in GTO's. He had a Holley he had bought new (12-398-11?) and still had it new in the box. We went down to the parts store and bought the barb fittings and hooked it up. I immediately saw the FP jump up to 6 1/2 lbs. and it began running much better, really good actually. Holley recommends 6 to 7 lbs. of pressure for this particular carb. Well that was all fine until it started leaking like a sieve from the new barb fitting where it hooked into the Earls AN type hose. I ordered a better fitting from MSC that fit the ID of the Earls hose better, leak was fixed. Fired it up and now it is back to running at 3 lbs! I was dumbfounded. I did some searches and found this place. I have read a bunch of posts to try to figure this out. The only thing I can come up with is we need a 1/2 inch supply line to the fuel pump (Thanks BearGFR). My question now is, if I have a 1/2 inch supply line from the tank will I need a 1/2 inch fuel pickup tube on the sending unit? I doesn't seem like just making the line bigger would do anything if the fuel pickup tube is still only 3/8 of an inch. Any thoughts are appreciated. Thanks in advance.