I finally tracked down a really nice factory cast-iron SBC intake manifold that’s correct for a Q-jet. It would be correct for a 327 ci engine. My purchase included a gasket and also a stainless metal plate. The metal plate has 2 holes that line up with the exhaust crossover holes. The stainless steel plate holes do not connect. How important is it to use this stainless steel plate? Is it supposed to be positioned above, or below the paper gasket? The picture below is a copy of what a vendor on eBay says about what he’s selling.
What IS important is that the carburetor, mounting gasket, stainless plate (if used) and the intake manifold are ALL from the same year engine!
Plates were not always used; different plates were used. It all depends on everything matching.
Not that mismatched parts will not work; but it adds a degree of difficulty in checking everything to make sure everything seals correctly, including exhaust.
Jon
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
Hy guys, in the days when the stainless plates (heat shields) were used there was a base gasket on the manifold, the stainless plate (heat shield) and the carburetor mounting gasket. Without the heat shield the fuel is boiled out of the float bowl. I know this because a friend removed his Qjet and rebuilt it he threw the heat shield and base gaskets into the garbage, next week after the rebuild of the carburetor he installed the carburetor using the one base gasket that came in the kit. He called me and asked me to come over and help him figure out where he went wrong, as the engine would not run for more than a few seconds, when we removed the carburetor and I saw the heat shield was not there I said why had he left it out, he said he didn't see the value or purpose of it. I asked him what he had done with it and he told me he threw it in the garbage, it had been a week so the garbage had been picked up. We had quite a time identifying the part and getting one sent to our local dealership, his car was out of commission till the next weekend. A famous GM engineer (who's name escapes me) once said "parts left out cost nothing and cause no service problems", In other words if the engineers bothered to put a part in a vehicle, it was there for a reason, hope that helps.
I never reused the metal plate under a Qjet. I used the exhaust insert restrictor for the head to intake on both sides. Then I used the 1/4" thick gasket under the carb. It was what worked best for me ðŸ‘
Last edited by fattboyzz; 03/25/20248:05 AM.
1962 C10 with a 235 6cyl -- all of the drive train seems to be original. Some of this story is in the Side Lot Some people like a new truck. I liked the old ones.
Since the intake is a 1968, it would be important to check a Chevrolet parts manual to see if a plate were used.
The Rochester manual doesn't show one, but Rochester didn't show all of the plates, and I don't have the Chevy manual.
If it is supposed to be there, it should be there.
Jon
Good carburetion is fuelish hot air The most expensive carburetor is the wrong one you attempt to modify. If you truly believe "one size fits all," try walking a mile in your spouse's shoes! The Carburetor Shop
I’ve read everyone’s comments. Thanks. I take it the metal plate gets sandwiched between two fiber gaskets? If not, does the metal plate go above or below the fiber gasket? *EDIT* I have a 1967 C10 truck FSM. That should give me the answer. Duh! Not sure why I didn’t think of it earlier.
