This is probably a stupid question for most, but I'm a body guy, give me a break before you laugh your a**'s off. I have an ford 292 with alot of miles on it, not more than the space shuttle but still alot Odometer says 95,000, i'm certain it has been "gone Through". Here is the question, what are safe operating RPM's for this tired engine? I am fooling around with gears in the rear. It had 3.70's and am changing it to 2.75's for a little more highway speed. 2.75's @ 65mph=2078 rpm. Am I running the engine too slow going down the road? Will I be 'Lugging" it too much around town, will it have enough pooop to pull it down the highway????
I had a 56 and it floated the valves at 4500rpm.That was all she wrote.They don't wind very high in stock form.I would use the 2:75,thats about what mine had and it would do 105 which isn't much but it was bone stock.
Can you say SLUG !!! 3.08-3.10area is as high as I would go. Manual or auto trans? Auto you can live with a bit taller gear than a stick. Personally if stick something in the 3.30s would be as tall as I would go. Those older design engines were designed to cruse in the 2500-3500 range and that would still give 75 with the 3.70s . What do I know ,only been screwing with cars for 50 + years.
Thanks guys, Guess I was in too damn big a hurry to mention that it's a f-100, (Hum, wonder what the weight difference is between the cars and pickups), with a 3 on the tree. I'm gon'na try the 275's and see just where I end up. If there too tall, well I guess we'll know better next time. I'll keep you posted later Thanks again for your input! Fenderless
My friend runs a 56 f100 with a stock y block and a 2.73:1 rear gear. He says it runs good about 75-80mph and knocked out 18+mpg on the way to the f100 supernats.
The Jalopy Journal
