Im swapping my 351w from stock 2bbl to edelbrock performer and holley double pumper 4bbl. The truck I took the manifold off was an 86 F250 and it had the standard intake manifold gaskets. When I called up my parts place, though, they said that on my truck since its the HD 8600lb gvwr, I have some metal pan underneath my intake manifold that acts as a gasket. Has anyone heard of this?? If I have such pan, could I just use normal gaskets like the ones used on the donor truck? Also, they asked me what "port sizes" I have. How do you measure that?

 

I have installed two performer intake manifolds on 460's and have used either the Felpro or Edelbrock gaskets. They match the ports fine. I have a valley pan installed below the intake but it does not extend into the intake gasket sealing area. You should be good to go with either of the products I have mentioned. You will see right away if they match the ports or not.

 

thats usually a splash shield to keep the intake from getting heated too much under the carb (although I have seen these on some GM 660's) your smallblock should use regular intake sides and the neoprene ends, which you dutifully discard in favor of some good ole fashioned rtv

 

Well, I pulled off my intake and I have the metal pan. So, do I have to buy a new one or can I reuse it? Is it even necessary to have? What neoprene ends are you talking about quaddriver? thanks

 

If you do a search this topic has been discussed at length.

 

Okay, I searched and ive come to the conclusion that you dont need the valley pan If you dont run an EGR. Is this correct?

 

I would run the valley pan. The factory runs exhaust gas through the middle ports of the intake manifold to provide heat underneath the carb to make it run better when it's cold. If you do not use the splash shield, then oil will hit the hot spot under the intake, and coke up. It will build up into a large carbon mess that can break off and fall into the engine. The shield deflects the oil away from the heat of the intake.

 

Yeah, but arent those ports covered by the manifold?

 

No. The stock manifold and most aftermarket manifolds have those ports. Just look in the very middle of the intake on both sides. Some race intakes do block these ports off.

I see you live in New Jersey, so I would definitely not block the ports off. You will have a cold natured beast on your hands in cold weather.