I am hoping that someone can help me with a gear whine issue. I have a 69 firebird with a newly broken in sbc406, 10:1 comp, ported 461 feulie heads, xe274h cam, air gap intake, etc. Tranny is a freshly rebuilt super T-10 (2:88 first gear) Rear is a Mopar 8 3/4" (489 casting) with a 3.91 and a posi.
I took the car out late last night to a very remote straight stretch of open road for some personal test and tune practice. I've gotten used to the th400 but I wanted some practice with the T-10 running it hard and experimenting with luanching techniques running BFG radial 275-60-15TA's(not the drag radials, the street tires) I gave it around 15 hard runs through 3rd gear in three sessions. Everything went well. After I was done I pulled over and checked the basics again.
On the way home I noticed what sure sounds like a gear whine in the rear axle only when I let off the gas. It will do it in a 4 gears. Its not a brutal sound or anything. It's an even consistant gear whine sound starting as soon as I let off the gas and stays until I give it just the slightest bit of gas again. Other than the noise, it runs great. No change at all. No gear crunching noises, no popping, nothing intermittent. I took it for a short ride this morning, same thing.
I was planning to bring the car over to ATCO Raceway (NJ) tomorrow for its first time out with the new motor tranny combo. I have a feeling that is not going to be a good idea. Any ideas guys?

Thanks,

George