Anyone measuring this... The only ACCURATE way is to use a home-made "feeler gauge" and check at all the points in the tunnel... a tape measure or "guesstimate" wont work.
I've heard a lot of speculation on this topic...but very few have taken the effort to do this accurately.
I did this in Seeley lake this past year.. and the 2.4" tracks had 1/4" - 5/16" clearance at the top of the tunnel using some "truth sticks" that I brought with me to check.
I can tell you this and Curt at FTX will back me up on this one, if you ran the RUSH bulkhead heat exchanger you will not have clearance for stock track/drivers without further work.
There are some coolers in the works for these sleds in the aftermarket for hop ups...
The stock coolers are more than sufficient for the stock motors.