tri power manifolds

[dunhamfield]

Are all the 3 deus manifolds lo-pro?? With the smaller ports?
I am understanding that you must match small port manifolds with small port heads and likewise with large ports.
How do you know just by casting numbers if a manifold or head has small or large ports?

 

[Ronnie Russell]

Terry, All 3x2 348 intakes are designed for the smaller port heads. I would not call them lo-pro, afterall, how could an engine with 3x2s, 11 to1 comp., solid lifter cam, etc. be considered low performance? The common 409 heads with large ports end in the numbers 690 and 583.

 

[jrpontiac]

Ronnie, are the 586 heads large or small port. I thought they were the large port heads, but I was planning on using one of my 3x2 setups on them. I'm I going to have an issue.

 

[SS425HP]

intakes

ONLY the 583 and 690 heads are the large port. The rest are the smaller port heads. Different size valves, but near the same on ports. The 690 and 5 83 heads have the bolt hole between the intake ports raised above the ports. The rest are down between the ports. I don't know if your 3 deuce manifold will work on the 690 or 583 heads. I would think you would have a problem sealing them off with the gaskets. The bolts that go between the intake ports will not line up. That could cause a vacuum leak. There was never a 3 deuce manifold for the high performance heads that I'm aware of. Not even an aftermarket one. If you want to stay with the 3 deuce intake, you will need to use the smaller heads. At least that is my opinion.

 

[dunhamfield]

Ronnie, maybe you could hook up with Bob and ad to the description of intake manifolds and heads and exhaust manifold casting numbers weather they are small or large ports....

 

[1958 impala]

You should have no problem with matching 586 heads with 3x2 manifold the heads are same basically as 1147 heads I think you are confussing port size with valve size the 586 heads do have the larger valves than stock 348 heads but the intake will mate with 586 heads.

 

[Ronnie Russell]

Terry, Our fearless leader has already put together a great list of casting numbers and descriptions. Simply go the home page and click on 348-409 engines and you can view all the numbers. In three months you will know all the numbers by memory. It is just something that W-head guys learn. gotta know the numbers.

 

[dunhamfield]

Terry, Our fearless leader has already put together a great list of casting numbers and descriptions. Simply go the home page and click on 348-409 engines and you can view all the numbers. In three months you will know all the numbers by memory. It is just something that W-head guys learn. gotta know the numbers.

Yes I have viewed the valuable information on home page... but in the descriptions of casting numbers it is not mentioned whether or not if they have large or small ports.
This would be very helpful information to us guys that dont know..

 

[Ronnie Russell]

Terry, Please review SS425HP post. That pretty much sums it up. I would gladly answer any question if I could, but am unsure of what you are asking. The 690 and 583 heads are large port and require the #881 2x4 intake or the aluminum single 4 intake (#678 and #463) All other castings are for the smaller ports, (except z-11) There may be some rare 1961 parts that I am not familiar with that may be exceptions. Hope this helps--- if not, I will try again. Also if you dont have one, Showcars offers a hard copy catalogue that has many numbers and descriptions. If you dont have one, you need one. Good luck