72 LT1 Carb attachment

[Gary S.]

Good afternoon to all. I am reinstalling my original Holley carb on my 72 and I referenced the TIMJG as well as the AIM for fastening torque. While I think that the AIM value of 120-168 in-lbs seems low, I will go with it. The question I have is in the attachment itself. The AIM shows nuts without washers while the TIMJG says "1972 nuts with flat washers under them".

Am I missing something or which one is correct?
Gary

[Michael H.]

Re: 72 LT1 Carb attachment

Gary,

Actually, the 120 in lbs figure is correct. That's 10 foot pounds, which is actually quite a bit for a brittle piece of Holley carburetor base plate. I've seen a LOT of these with broken ears from slightly over torquing.

Joe Lucia may be the best on the washer part of your question but I remember no washers at all under the mounting nuts on these units. Could be wrong tho.

Michael

[Gary S.]

THank,s how about the bracket

item 3959444, that holds the fuel line in place? Does anyone know if it fits directly onto the carb attaching stud or does a 1/2" nut go on and then the bracket, follwed by another 1/2" nut? Sheet A6, page M381 of the 72 AIM. The car came to me with the setup as I described but the AIM seems to show carb ear, bracket, nut.

Michael, thank you for confirming that. While I knew the TIMJG was correct, it sure sounded like a small value.

Thank you,
Gary

[Michael H.]

Re: THank,s how about the bracket

Would be best to wait for a response from some of the C3 guys on this. 68 and newer is out of my league and I don't want to steer you in the wrong direction. I still can't tell a 76 from a 77.

[John H.]

Re: THank,s how about the bracket

Carb base, bracket, nut - no nut between the base and the bracket.

[Joe L.]

Re: 72 LT1 Carb attachment

Gary-----

I would say that the JG is incorrect on this. No washers were originally used under the Holley carb attaching stud nuts(i.e. between the nut and the throttle body). This was also true for Rochester carbs----no washers were used under the nuts on the 2 rear studs or the 2 front bolts. They should have been used, but they were not used. I expect that a lot have been added over the years and that may be where someone came up with the "idea" for the JG that they were original.

[Gary S.]

Re: 72 LT1 Carb attachment

Thanks to all who responded on both questions. I reviewed the Rochester diagram and they don't show washers either. I will assume that the JG is not correct.

Gary