Intake Gaskets
 

I'm replacing the intake gaskets on my cast-iron 427 medium riser stock cast iron heads heads I purchased Fel Pro #1247S-3 gaskets. My question is it looks like there is a extra port on each head near #2 cylinder one on each side. However there are no provisions in these gaskets they just cover up the ports. What are the two ports that seem to go nowhere for? By the way I have a Ford 2-4 barrel manifold.
Thanks.

Intake gaskets
 

Any body have idea what these ports are for? I'm waiting to install my intake until I fine out if I need these ports open or not. If I need these ports open why are ther no holes in the gaskets for them. Any info would be appreciated.

Thanks

I'm not seeing any pics on your post so if I had to guess maybe you're looking at the heat crossover ports?:confused:

Here, I found a video showing the heat x-over. I don't even have it on my heads, but I've seen them on old stuff.:rolleyes: Here, he uses a beer can to block it off. That's the only port I can think of that you might be talking about.

Intake gaskets
 

That's it Patrickt.....thank you. I don't know about putting a thin piece of tin can to block off the port. I worry about an intake leak.

I have no experience myself in blocking off that port, but I have read that gases will eat up the gasket over time if you don't put something there. I have also read that, once upon a time, little metal pieces came with the gasket set for doing just that. Surely someone on here has blocked it off but, if it were me, I'd just hone a small piece of stock that fit in there flush and tuck it in, maybe with a dab of JB Weld.:cool:

I think the S in the FelPro part number means they are steel reinforced. If you look closely you can see a thin sheet of steel laminated in the middle of the gasket material. I used Cometic steel reinforced intake gaskets on my 351W and did not add any kind of filler piece. Only about 2000 miles since, so time will tell.

The heat cross over provides heat to the intake to help with the warm up cycle after a cold start. Most cars in the 60s also had a spring or thermostatic coil heat riser valve in the pass side exhaust to close it down when cold or at light throttle and force exhaust back through the manifold to the driver side exhaust system - which was why the pass side exhaust system back in the 60s would always rust out before the driver side. Once the engine has run awhile the manifold is going to get pretty warm any way from crankcase heat and it's purpose then is mostly nil although if unblocked it can add enough additional heat to promote some carb percolation issues with modern fuels. Some cars had intake mounted thermostatic choke coils that needed the crossover heat to work properly but the Ford 2x4 intake was not one of them. Best to block them off unless you are having cold start issues you can't live with. One benefit of the heat crossover is it does act somewhat like an H-pipe in the exhaust system to help mellow out the exhaust sound - but to a much lesser extent than a true H-pipe. I've never experimented back and forth but I've heard from some of the vintage Corvette guys that they can tell very clearly a difference in exhaust sound on a motor with a blocked crossover versus a motor with an unblocked crossover.