Originally Posted by workingonit

What weight gear oil are you using? In the last iteration of my Chevelle, I was using a 90/140 (or thicker?) gear oil with some additives, that my friend (who built a lot of drag cars back then) had formulated for him, and kept a 55-gal drum in his storage room.

It may have been Royal Purple, which he seemed to have a special relationship with, as he could get their packaged oil products at ridiculously low prices. I would stop by their local distributor sometimes, on my way home from work, to pick up some more for him, as it was only 20 miles out-of my way but he'd have to drive 160 miles round-trip to pick up (I'd take it to him the next trip out to his shop, 50+ miles from my house).

Anyway, it was made for N.Texas drag racing, usually from March 1-Nov. 1, so it would thin out nicely during warm/hot weather; but, in cooler weather, I'd have to drive extended runs in the pits or return roads, pre-race, to get it warmed up (couldn't just warm the engine up static, as the tranny and diff needed to be at operating temp, too).

Since you're in S.Louisiana, think about using a thicker weight gear oil than you normally would, as your normal ambient temp is even higher than here in DFW. But, watch out for polar vortexes if you plan to drive without a gradual warm-up first.

About my car's top end: it was a heavy car (3800-4000 lbs) with a moderate stall speed convertor (4500 rpm) and a high starting gear ratio (1.76:1) in the trans-braked Powerglide, two-speed transmission. Thus, it was slow off the line, compared to most of the cars in my class, usually stripped-down Rustangs (65-68, or 5.0 bodies with Chevy BBC'S in them), other 64-69 General Motors A-bodied Camaros, or 62-65 lightweight Exner-styled full-size (or later B-bodied Road Runners & GTX's) Mopars, so that's why I went to 4.88 gears, for more oomph off the line.

It definitely made some noise, because I'd hit the 1/4-mile at 7200+ rpms, which is a bit high for most BBCs, but we used the strongest parts available so it'd hang together (I set the rev limiter at 7600 rpm...most other BBCs had theirs set nearer 6800 rpms). And my un-tubbed wheelwells, and class rules, made me run 28" diameter slicks, so top end speed was limited there too. My best was 10.75 secs @ 127 mph on an ill-prepared track (oiled-down in a prior race). I'm sure the sound level reached was pretty high, and contributed greatly to my ever-present tinnitus, that came a few years later.