Hello!
I have a 69 Corvette with 427/390hp BigBlock and want to change the cam. I want to have low end torque as much as I can get and idle well below 1000 rpm (NOT rough idle wanted).
Regards, Günther
For my L88 clone 427 engine in my 69 Coupe, I used the cam specs for the L88. I'm sure I bought the real L88 cam from GM performance parts. It had one thing you posted that you don't want..low torque at low RPM's. For the other thing you wanted was an idle at stock engine rpms. I had a 50 pound flywheel so it would idle at normal RPMs.
The L88 engine power at higher tach values was just explosive. However, with the stock cam, getting the car rolling from a city street stoplight was painful...I had to slip the clutch to get it rolling due to the low torque from the engine at off idle. I bought a 5 speed, a Doug Nash 5 speed, due to the car's 3.08:1 diff. This was a perfect tranny...no problems getting going in city traffic off a traffic light. If I remember correctly, the Doug Nash 5 speed with a 3.08:1 rear end was pretty much the same as as a stock tranny with a 4.56 to 1 rear end in first gear. No problem getting rolling.
The Doug Nash 5 speed is now marketed as a Richmond Gear 5 speed. It looks the same, however my understanding is that Richmond cheapened the tranny by lowering the torque ratings of the engine. For a stock 427/454, the Richmond is just fine.
Since I wanted to run much more HP than a stock BB, I decided to switch to a Tremac 5 speed. It's rated at about 1000 ft-pounds if I remember correctly. However, you can't reasonably use a Tremac with a 3.08:1 rear end. To go with a Tremac 5 speed, I had to change the diff from a 3:08.1 to a 3.73:1 differential. I have the same Tremac 5 speed in my 68 SB. The 68 has a 3.73:1 rear end. The 68 will, like it's sister, in Tremac 5th gear cruise at 70 mph with about 2000 rpms on the tach. However, at low engine RPMs taking off from a stop light, the Tremac speed has very much adequate torque in first gear.