High rpms with SB Chevy and 4 speed tranny

[AKA DUKE]

This is my first 77 FJ40, I just bought it, put new brakes on it and its now drivable. My question is it has a SB Chevy and the 4 speed tranny, as far as I know it has the stock 4:11 gears.
I took it out for a drive and at 40mph I am running 3500-3800 rpms, at 45-50 mph I am running 4000 -4300 rpms.
I called the previous owner and he said he could rive it 60-70 mph on the highway, I dont see how. Is it that the tranny is not compatible enough? if not what tranny is? or whats the best way to make it so I can drive more than 40mph with runninh such high RPMS? Any suggestions on what to do.Thanks in advance for any help.
The new guy.

 

[Mace]

A. what tach are you using?

B, is it in low range?

 

[AKA DUKE]

Ok I feel really stupid now!!!!!! Thanks for pointing out the obvious. The shifter is not there so assumed it was in 2 wd, stuck a shifter in it and is was in 4 high. Boy do I feel stupid.

 

[Downey]

High gear in all trannies is 1 to 1 (unless you have an overdrive tranny), that means when you install a Chevy V8 and leave the same tires and gear ratio, the V8 revs the exact same RPM's as the stock 6 cyl.. The only difference is a Toyota 6 cyl. is about to fling apart at 3,000 rpm and a Chevy V8 is alittle above a purr at 3,000 rpm.