Hello everyone - I recently acquired a 1977 4.9L Inline 6 with the 3speed manual transmission. Is it safe to drive at freeway speeds such as 70 to 75mph? seems to go 55 and 60 quietly, but I have never had a 3 speed before.

 

Didn't have a tach in my 71 300 CID, would guess at 70 MPH would be running around 3000-3200RPM. See no problem, perhaps someone with a tach will chime in.

 

assuming it's in good shape, should be fine.
my 82 top speed is around 85mph, with the tailgate down, with a tailwind, goin downhill. lol

 

The inliine 6 was famous for 4:11 gears you may not get but 70 mph top end.

 

Never had mine above 60.

 

The only way to know for sure how fast it will go is to go out and run it wide open for a few miles then you'll know and have some fun doing it

 

Dude, I have to know where you drive at!?!

 

I drive up and down Interstate 75 between acworth and ressca, GA to work and back. About 45 miles each way. Truck has been doing just fine.

 

That's about right. I've got an 85 4 speed and I get about 65-70 before I dare go no further. It's a great hauling truck. hauling *** however, not so good

 

My truck is no speed demon. It seems built to toil rather than go fast. I think I hit 60 the other day going to the dump and the tach was hitting 3k.