that is not the problem caused by milling your heads. its been a while but i think it makes the intake bolts not line up or the intake runner gaskets prone to sucking oil??

Man, we need to talk. I have done this with great success. But, the heads need to be angle cut, then the intake cut 90 degrees to recreate the intake sealing surface. Then advance your cam timing 4 degrees and it will wake up. In order to tell you how much to cut, you need to cc the heads and the combustion chamber. I used GM .018 compressed Stainless Steel gaskets also used on the 88 to 90 7.4's from merc to further up the compression. When I get home I can find the part number.

Tom

Standard Merc gaskets are .030 compressed and Felpro marine gaskets are .039 compressed. You get the same results using a thicker gasket and milling more, so decide on a gasket first then mill accordingly to gain .030. This should reduce the chance of having to modify the intake.

How about dry-sump? How much would that cost?Just a thought
pat W

Mike,
You should first measure volumes and figure out what compression ratio you have now. Just because the pistons are 8:1, doesnt mean much. Measure, measure, measure....
Next measure your deck height, you may want to close up your squish area instead of milling the heads.
Next, the figure that was mentioned.. .005"=1cc is correct for a BBC head and .010"=1cc for angle milling. It takes alot of material to be removed from the chamber to equal 1cc.. I know, I was looking for 6 or 8cc a while back.....
Next when you measured your PTV clearance, what about side clearance, pocket to valve edge?. If you cut the head it may move things closer to the edge... measure, measure, measure. Something the pros in this area dont do????
Next, if you cut too much off the head, you will need to take some off the intake or the intake flange of the head. Normally, you cut the head and when you do the port match on the intake, you will see if you need to remove material from the intake.
Oh yeah,, pick the head gasket you are going to use, first.. opps, Hey I ain't no pro..
That will affect your ratio.
Notch the block on the intake side to relieve it.

Now that all of this is done, get a whipple charger and go like hell..
I pulled this from memory..which has been failing me in my later years. But a few beers at the legion may help, if you have anymore ???

Dick

Well, I went and visited my heads yesterday. Spent a lot of time talking to the shop owner. We decided against decking them down any (for now). With my low compression pistons we would have to take too much off to be of any real benifit anyway. We are doing a good 3 angle valve job, fairing the valves a bit (to inprove air flow), new seals, and smoothing out the intake side of the heads in the combustion chamber (it's all I have the money for). Add this work to a better port matched dual plane intake and line bored block and I should see some benifit.

Any thoughts?

Mike,
Any good machine shop should know how to make the correction cut on the intake after you angle mill the heads. Just make sure you give them the intake you will be using.
Also , my "airflow technician" friend has found as much as 40hp using a certain type of valve and one of his valve jobs. If you already have your heads at a shop I guess it's too late.
Add a roller cam, (not a solid , you West side guys are too lazy to lash valves ) some 1:8 rockers on the intake side, if you have room.
Up the CR as much as you can. Every little bit counts.

Chuck

don't forget to bore notch the cylinders!!!

don't forget to bore notch the cylinders!!!

If the eng is apart now check the deck to piston clearence on most big blocks it is about .025 have the block decked shave the heads .020 to .030 and use a thin head gasket. Flat top pistons have better flame travel than domed pistons. I have used edelbrock RPM peformer with good results. Unshroud the valves and bore notch the intake side after you assamble the eng it will be to late as for the intake you can sit it on ank see if the heads and intake set straght with each other no big deal.