2x4 Manifold Problems

[SNAKEYES]

I have a blue thunder manifold (the original style that takes 2 holleys). I got it a few years ago off of ebay. I have the Ford Racing 306 crate engine. M-6007-302*. So I,m getting ready to install the manifold on the engine with the gaskets that the instructions that came with the engine says to use. I notice something doesn't look right.

PROBLEM: The top of the manifold doesn't cover the top of the intake port on the head very well.(even with this issue the ports on the manifold can flow freely into the ports on the head because the heads have large ports)

I called Ford Racing and the guy says that engine has raised intake port heads, and I should not use that manifold, because 80% of the time they do not seal and suck air at the top of the manifold. He said to make it work I'll need to have the upper edge of the manifold welded up some. then resurfaced.

The original gaskets are .065 thick. I ordered a set of Mr. gasket 213 gaskets that are .125 thick. that raised the manifold up to where it looks like it might seal now. Has any one run into this before?

Any ideas? I want to use this manifold. To cool to give up!

Thanks guys, mike

[Jim Doak]

I also have a Ford Racing Parts 302 crate engine (M-6007-XB3M). It's the 345 horsepower engine with the 'B' cam and the X303 GT40 aluminum heads.

I've been running a Blue Thunder dual quad intake with twin Holleys on my engine for over two years and 8,000 miles. Maybe I'm one of the 20 percenters, but I've had no problems sealing the intake to the cylinder heads. My biggest issue was that I needed to trim one of the 'ears' on my distributor housing to provide the necessary clearance between the distributor and the intake. I also needed to install a small diameter cap and rotor on my MSD distributor.

Anyway, good luck on your install.

[SNAKEYES]

Jim I have different heads. Mine are M-6049-X306. They say the ports are raised. The fellow at Ford said I could use the edelbrock duel quad set up on these heads. But I would like to stay with the blue thunder if possible. Thanks.

[BigLeo69]

the other thing that may occure is with the raised ports is ur headers
on the heads to intake the ports being taller and not pairing with the intake u could try some shellac with the gaskets it may hold
good luck

[Bob Cowan]

Some performance heads raise the intake ports for a better flow path to the valve pocket. And sometime s head porters (like Gordon Levy) will raise the top of the port for better flow. In those cases, a standard intake won't fit, as it also needs raised intake ports. There is no way to adapt the manifold to the head. Your only two options is to modify the manifold as you stated, or buy a manifold that fits properly.

Been there, done that, paid the big bux for a new manifold.

Also keep in mind that you'll need a differant gasket, too. It's usually the Fel-Pro 1262R. This gasket is almost impossible to find locally, so I always keep 1-2 on the shelf.

[Eazy_P]

I just went through this exact issue to get my Hampton Blower Intake Manifold to work with the AFR 225 heads (Fel-pro 1262R gasket) on my 408W.

I had a local custom welder add about 5/16" of weld (TIG) in 4 spots on each side of the manifold flanges over the intake runner ports. He said it was a very simple job and only charged me 1 hour shop labour charge.

Then I took it to a machine shop and they planed it smooth (another 1 hour shop charge), turned out really nice in the end.

HTH