I have a 5.3 that I am putting in my '67 Camaro with a 5 speed manual on a budget. This car will be a DD and my goal is close to 400HP and the best mpg I can get. Obviously the setup needs great reliability and driveability. I have a TR224 112 cam and long tube headers. My question is what should I do for heads? I have been offered a set of 806 LS1 heads (perimeter bolts but heads come with valve covers) that have been fully ported and milled .025" for only $200. I don't want to spend any more than $200 on the heads so 243s are out of the question. The way I see it I have three options:

1. Do nothing and use stock heads
2. Mill the stock heads
3. Buy the 806s

What would you guys recommend?

 

After doing more digging I am not comfortable milling the 806s about .035 more to get the cr I'd like. I'm thinking milling the stock 706s would be best.

Should I mill the 706s .040 and call it good?

 

Your hp estimate is a little off.

 

I figure if LS1 guys can hit 400 with just this cam and LTs I should be able to get close with some head work. Don't really care if I end up short, just a goal. Car will stuff be fun as hell.

Thanks for the help.

 

It's hard to get 400 at the wheels with a 5.3 but 350-380 is not far off. If your on a budget, I would stick with the factory heads.

1. There cheap because you already have them.
2. You can do a very minor clean up your self and net some really good gains.
3. Every other factory head is going to lower the compression with out milling.
4. In factory form the the flow numbers on the stock cathedral port heads are around 10 cfm different so what are you really gaining if you have spend a few hundred to buy them and then spend more money to mill them to at least maintain the same compression so you can see a small gain.

Stick with what you have and give them a little internal clean up in the bowl area, upgrade the intake side, have them cleaned with a good valve job and milled to bump the compression slightly.

If you clean up the bowl area and lightly blend the castings your self you will save the most money.

You could probably pick up some good used 2.0 valves for the intake side for around $50 I believe you can get new replacement's for around 10-15 each if need be.

Then a good valve job and milling will cost you a few bucks and this alone may eat up your $200 budget but you will be close.

your going to need to consider springs too which can run around $150-$200 range

Hope that helps.

Other wise we have some sponsors that have some really nice CNC ported packages that start around $899 completely ported and assembled with better springs for a mild cam.

I know both SDPC and WCCH have a stage 2 package for the 5.3 heads that's really hard to beat for the price.

 

That's very helpful info, thanks a lot!

 

Your Welcome!

 

How much should I mill the heads? I’m thinking .030 or .040? Looking for a nice bump in CR but not at the expense of reliability, only want to run 91 octane.

 

Approximately every .007 of milling equal 1 cc on the head. There around 61 cc to begin with. I don't see why you couldn't go .030-.040

.040 may be the limit though. The more you mill the thinner the deck surface becomes.