[blykins]

None taken.

As you know Mike, the newer TKO 600's don't share the same gear ratios as the older 3550's. The 1st gear ratio in the 600 is 2.87:1 instead of the granny-gear 3.27.

I try to match all of the drivetrain components with each other. A cam that is still inefficient at 2000 rpm doesn't need a higher gear ratio that puts the rpms right in that range while cruising.

A larger duration solid cam like he has chosen, especially with a tight LSA and lots of overlap, will not be as friendly as some of the more streetable camshafts out there.

With the TKO 600, you have either a choice of a .64 or a .82 overdrive.

With a 3.31 rearend and a .64 overdrive, you would be taching 1500 rpm @ 55.
With a 3.31 rearend and a .64 overdrive, you would be taching 1900 rpm @ 70.

With a 3.31 rearend and a .82 overdrive, you'd be at 1900 @ 55.
With a 3.31 rearend, .82 OD, you'd be at 2400 @ 70.

I personally wouldn't match that particular engine setup with anything that would allow it to cruise under 2000 rpm at the normal driving speed.

With a revvier engine and less than desireable low-rpm street manners, I would rather have the lower rear gears.