Hi Guys, I've been doing my homework on changing diff ratios and doing some calculations on engine rpm. It occurred to me that I have no idea what the red line rpm is for my 327 engine nor do I have a feel for the rpm at which I can run the thing for hours on end. Do any of you have any specs or experience with this? I know when it sounds like the rods are about to come through the hood (a shame to ruin a nice hood like that) but wonder if I'm doing damage by pushing 3,400 rpm at 70 mph with the 3.90 rear end? Will the engine last a lot longer if it runs at 2,700 rpm with a 3.08 rear? What do you think? Tom in Steamboat '60 Apache Short Fleetside
A 327 will run at 3400 rpm, but it would be much better to cruise at 2700 and yes your engine will last a lot longer at the lower rpm's. I'd either go with the 3:08 rear or get an overdrive transmission of some sort.
