1970 vs. 1978 350SB

[Southpa]

Hi folks, been a while, eh? I'm finally getting my engine rebuilt by a local outfit. I've done lots of work on the truck myself, but where it comes to the engine I figure I better leave it in the hands of people who can do it right . It was long overdue, still running but sounded pretty sloppy.

We're looking at a 1970 350 "010" cast w/ 4 bolt main. Among other minor things (will list later) there was a crack in the block. They didn't want to risk grinding and welding as they wouldn't be able to provide the one-year warranty ie. not always a sure fix. So they found another 4-bolt main 350 block and assured me it was similar vintage as my original engine. My main goal is to keep things as original as possible. If I knew the block was cracked I would have gone out and bought a Crate and have done with it.

Anyway, the suffix code on the new engine tells me its a 1978, any real big difference here? Both engines have the same casting and bearing caps. But I see large differences in HP and torque ratings between the two. I know one (1970)is gross HP (255) and the later 1978 is net HP (165). I don't mind using a 1978 motor, I guess a lot depends on how you set it up in the first place. I'm going for a stock rebuild w/ the ramhorns, no stroking or anything and I'm replacing the original intake with a Edelbrock Performer intake and the old (assuming original) 4MV Rochester with an Edelbrock 650 cfm offroad carb. I was told with that setup you can install and basically forget about it.

They also found:
one seriously cooked exhaust manifold, I mean melted and then cracked cast iron, under the heat collector.
Bottom of the timing chain cover was worn thru from sagging timing chain.
Two lobes on the cam were worn almost flat
Hole in one of the valve covers, was wondering where all that oil was leaking out.

I was driving this truck all this time (since 1995) on unleaded gas without hardened valve seats, surprised its lasted as long as it did!