351c wont start, help

[1969_Mach1]

Mustangmike and I both have Windsor motors, different sizes but Windsor's.  Windsor's do not use a belly pan under the intake manifold, merely intake gaskets to the cylinder heads and preferably RTV for the front and rear end seals.

Here are instructions to install the Edelbrock Performer intake manifold.  They do not mention using a belly pan gasket.  I think I would install the stock intake in the same manner as in the Edelbrock instructions using Fel Pro Performance gaskets or the Edelbrock gaskets mentioned in the instructions if they are correct for your cylinder heads.  Without using a belly pan gasket your cast iron intake will stay cooler than an aluminum intake.  Some  performance intake gaskets come with plugs to block off the heat crossover passages.  If you do not need the heat crossover for a choke or anything else, you might want to think about installing them.  The first 5 minutes or so after cold weather starting might be affected a little.  But, it will help keep the intake manifold cooler.  The heat crossover is probably the biggest heat source to the intake manifold.  You kind of have to decide on plugging the heat crossover passages or not depending on the weather in your area and how much cold weather driving you will do.

https://static.summitracing.com/global/i...d351-C.pdf

[JTS71 Mach1]

Use the Fel Pro performance gaskets, and forget the belly pan. If the intake has a heat passage block it off. I'm not a hundred percent sure, but I don't remember my 351 Cleveland heads, or the intake, having a heat passage??? God I wish I could remember all this stuff better. But you don't need either one. Plus the gaskets should be more forgiving then the metal pan where the heads, and intake meet. Especially if they have been milled a couple times. Most modern intake gaskets, have the blue silicone sealing lines on them. If they do. "Do Not" use any sealant or glue, to hold them in place, as this will cause leaks, with the sealing lines on the gasket. Hope it helps. 

JTS