78 sierra grand...whats in it??

[richardGMCwilson]

Hey all!

 

I was thinking of picking up a 78 sierra grande 1/2 ton stepside short box. It has a 350 with a 4 barrel on it wich i thought was not factory but the guy said it was. i think it has the SM465 and NP205 in it. the trans case is 2 hi, 4 hi, 4 lo and Nuetral. 1st gear is so incredibly low geared i am assuming its the SM465. 3:73 gears in it. i dont know the axles in it. i was wondering if anyone on here could help me identify axles and confirm trans and trans case? also does anyone know ratings for the engine in it? hp and tourque....just out of curiosity??? thanks in advance

Richard

[ifixedit]

By 1978 the small block Chevy had been basically 'killed' by emissions and low compression figures and were developing the lowest figures known to man. The highest rated 350 in 1978 was putting out around a whopping 175 HP (on a good day) at best and that was likely in the Corvette, this one is probably in the 165 HP category. I can't help on the trans case but the tranny itself I would think is either a TH350 or TH400. As far as determining rear axle gear ratio, there should be a metal tag somewhere on the rear diff, you'd need the numbers off of it to determine what rear end and gears it came with which you should be able to reference online or possibly even at either an auto parts store or a GM parts counter.