7000+ RPM requirements

[Doubt_Incarnate]

is it even good for pushrod motor to spin over 6k? theres alot of possibility for instability to do its thing isnt there?

[geoffinbc]

No its not a problem. But you do need the right parts.

[Blue89rs]

Okay, I'm on the garage computer right now and the heads are on the bench beside me. The part number is 10048651 on both heads. The upper intake is a 10100017 and says "3.1MultiPortFI".

So if I put FWD 3.1L pistons on a RWD 3.1L head I'll be okay, right? Worst case I'll just put the 2.8 iron heads back on, or will that even work?

[sharkey]

3.1l aluminum head pistons and ironhead will end up with something like 7.5:1 compression. now if you use aluminum heads with 3.1l ironhead pistons you will get the high compression.

[Blue89rs]

Okay, then I should be good as along as I use the aluminum heads. Too bad I have the wrong heads. According to GM, I need part number 10048649, not 10048651. Do you guys know the difference between the two aluminum heads? If its just the port size I have no problem porting these heads myself.

[Doubt_Incarnate]

im not fmiliar with numbers but after 94, maybr 95 they motors looked different, 3100sfi or even the 3400sfi, those have the best heads. the mpfi and sfi intakes arent interchangable.

[Blue89rs]

Hopefully its just the porting that they did on those intakes and not the valves. I think I'm going to go ahead and start working on the heads that I have. I'll order up a gasket kit and start the port/polish process. I should be done with them by the time the machinist is done with the block. WOOHAA! I'll update this post with progress pictures as soon as I get them.

[bszopi]

8649 and 8651 should be the same head. I've noticed that on 3x00 heads, the head I had in my hands and the GM part number were like 2 or 3 numbers off (ie, the 49 and 51), yet they were the same. I usually go by if its within about 5 of each other then they are the same.

[Blue89rs]

awesome. That makes me feel alot better. Now I just have to figure out how to do the intake setup and its a done deal. I fully intend to make public all of the stuff I found out to make this project work. I found descriptions of the head at http://www.sallee-chevrolet.com/Cyli...eads/4-6V.html , but it doesn't list the head that I have at home. So your information helps me out alot. Does anyone know if they ever made a RWD intake for these heads? I know that the 3.4L camaro's use the same lower intake as the iron head 2.8's but have a different upper intake. I haven't been able to find any site that lists this head for a RWD application. I believe the intake will be my biggest hurdle at this point.

[Doubt_Incarnate]

i think aluminum heads are fwd exclusive. maybe you can get away with the 3x00 bottom intake and custom make that twinn throtlebody setup you mentioned before.

[geoffinbc]

No there is no RWD intake for aluminum heads. But just turn the whole thing around.

I thoughy you were going to go with a 2.8L crank for this 7000RPM build are you not? If you are, you CANNOT use 3.1L pistons of any type.

[Corpse]

In case anyone would be interested; I am not really on the marklet to sell any of my goods but, I am broke so..

I have a set of Federal Mogul H562CP (+1.00MM) Pistons. Which are designed for 3.1 Iron Heads and have coated skirts, of course. but, when used with Alum heads they have very pleasing high compression levels. I will sell them very cheap.

I also have a set of 8 Pre-68 Small Journal V8 Connecting rods. Which, as we all know, can be machined to fit a 660 Motor nicely. these rods have been reconditioned and balanced but, are not cut and bushed for the 660 motor. you would need to have them machined.

I also have a set of reconditioned 3100 heads that are from pre-00 years. And, if you're in the market for Gen II parts, which noone is, I have an arsenal which I will sell parts from at extremely low prices as, they aren't worth anything to me really.

Sorry to post like this but, I figured it could be useful to someone.

"...you CANNOT use 3.1L pistons... " I have heard this type of speak before but, wouldn't it be possible to use a GenII/III high compression 3.1 piston on a GenII/III 2.8 Crank to achieve low compression? Or would that just cause a horrible flame travel situation?

-Dave

[geoffinbc]

LOW is right. I dont even know how low it would be.