Elsewhere on the Forum, there was a party trying to sell a set of Cartek LS6 Stage 3 heads that were bored to 4.125 and milled 0.30 for use mainly on a large displacement set-up. While I was not in a position to consider these particular heads by his drop dead date, I am in the market for a power upgrade and this offering raises some interesting questions I would like to pose to the group. As I have said before, I am not seeking absolute maximum power and am not willing to put up with loud supercharger whine or bad street manners in an agressive H/C job. My goal is relatively modest and simple (in my view): 400 rwhp in a '98 A4 and still be able to pass Taxachusetts state emissions.

Is reaching this goal possible with H/C (including headers)? I would think so. What "stage" are we talking here and is it possible to still end up with decent street manners and the ability to pass an emissions test?

Assuming we are talking no more than a good stage 2 set-up to reach this goal while still keeping a decent idle and good emissions, what would happen if I found a set of stage 2X, 3 or 3X heads at a bargain price? Could they still be used with a stage 2 cam to result in a decent running stage 2 set-up? Or would the mismatch cause problems? Is there any such thing as having heads that flow too well?

Lastly, if the heads I found were overbored and/or milled for a large engine set-up, could they still be used on a stock displacement engine? Or would there be problems with the head gaskets, flow pattern, compression ratio and/or emissions? In other words, how flexible can I be regarding heads given that my goal is power WITH good street manners and the ability to pass an emissions test?

Once again, thanks in advance for your help!

Monk

 

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Small cam and heads 11.61 119 mph 1.67 60 ft
a4 convertible
John Sr. blktie8