Tango,
It has a 350 with a 4L80E tranny with a 5.38 gear in the rear end. should have enough power and cruise down the road at 65 all day. the chassis and running gear is from an 2003 GMC W4500HD. That was the last year gm put a 350 in anything.
Shane

Shane
1959 Apache 3100 Fleetside
1959 Apache 3200 NAPCO
1957 Chevy 5700 Low Cab Forward
1959 GMC F370 LCF
Another 1959 Apache 3100 Fleetside
1959 Chevy 5700 LCF
1946 Chevy 1/2 ton
1958 GMC 600
1974 Elcamino SS