[ItBites]

Mine dyno'd 540 rwhp on a fluid (not inertia) chassis dynamometer. The build on my pump-gas, street 540 cid engine should have produced about 675hp at the crank. I have IRS and an automatic transmission.

Assuming 20%loss in the trans and IRS, 675 crank hp equates exactly to 540rwhp. I think 20% loss is a pretty good number for Cobras.

BTW, I custom built equal length (34" primaries) headers with merge collectors. I think a good exhaust is crucial.

Also, good tires really help the traction issue. The cheapest way to improving your car's ACTUAL performance is to shoe it with the best rubber you can buy. I run Toyo R888s, and lower the pressure.