[M&M]

Getting a set of cast iron heads from SD Performance. He suggested that I switch over from my current Performer intake to my '72 HO intake. (They are opening up the intake ports on the heads). I noticed the ports on the intake are a bad match to my HO gaskets, (Fel-pro). Thinking I should open up the intake ports to better match the gaskets. Figured I could just use my Dremel to do the job. Noticed a gazillion bits for the Dremel. Which one to use? Any better ideas are very welcome.

As always, thanks in advance.

[Skip Fix]

The Dremel sand rolls will do better than their bits. They are too small for aluminum and load up too easily even using some lube on them.

Better to get some Summit aluminum carbide bits and sand rolls that fit on a shaft like Standard Abrasives makes. Taper and solid. Aluminum will load up the bits unless you use WD 40 od Eastwood has some wax type stuff.

[steve25]

If you have raise the port roof by more than 1/16" to make a match than you need to match back into the manifold runner some 2", or just do not bother.
This will take forever with a Dremel tools small size and sanding rolls, but more than that if the heads do not flow more than 240 Intake CFM then the port mismatch will only cost you some 3 to 4 HP anyway at cam lifts of more than .500"
I would suggest that if you feel you must do it, than take it to a shop and spend 75 bucks to get it done, or invest in a cable type electric grinder like Eastwood sells which always ends up paying for itself on other projects if your a auto tinkerer!

[M&M]

Thanks guys. It is a street car, I only try to make it quicker for the "fun" factor. Hours of work and ~ $70.00 for a few more horses is just not worth it to me. I believe I'll leave well enough alone.

It doesn't matter since I'm not going to bother with it anyway, but the port missmatch is mainly side to side. Top to bottom is really quite close.

Thanks for saving me both time and money.

Mack

[boater bill]

I'm just finsihed the port match on a Torker 1. Used my die grinder with carbide roll and flame tips from Sears. Finshed with a sanding roll. Maybe total of 2 hours grinding to match the gasket.

[Pontirag]

a dremel seems like a pretty small tool for that job. I use a big old Makita

as for the aluminium sticking. for a little grinding you can get away with WD40 or oil but bee's wax works very well.

Jim Hand and several others have pointed out that if the intake is smaller than the head runner then you may not actualy need to open it up. and also in some runners where there is a hump on the side wall further down the head runner makes it pointless to match the intake interface because it just narrows back up at the hump.

be carefull opening up the runner in the head . some times you can grind through the push rod hole.

again , see Jim Hands Book

[77 TRASHCAN]

I'm with Steve. Maybe smooth up some rough areas, but pretty much leave the intake alone. Performance improvement by matching to intake, nearly zero. Leave that material on the intake for better gasket sealing.