i'm trying to get ready to buy engine parts to rebuild my 350 tpi...but a major step is the summit site has two options for engine, 1 being "chevy small block gen I" and the other being "chevy small block gen II (LT based engines)", now i know my motor isnt an LT1, but i wasnt sure if that makes it a gen I engine by default....help?

 

As far as I know we are still first gen. Second gen is the reverse cooled opti-spark LT1 and similar engines.

 

Yep, you have a Gen I. Gen II is LT1, Gen III is LS1/LS6, and I stopped paying attention after that. I think they're on Gen VI now (C7 LT1).

 

If it has a dizzy at the rear it is a Gen 1
( Gen 2 has the dizzy at front , Gen 3 doesn't have one at all )

However not all Gen 1"s are created equal.
You need to be aware of the break point, 86/87 where many changes were made .
Many SBC parts will interchange but be wrong if installed in the incorrect year engine ( without other year matching parts )

That is why you will notice on Summit / Jegs items listed as up to '86 or post '87

 

thank you guys. i'm not sure what year tpi it is, i know they have a difference with the intake manifolds between the years but wasnt sure of any other differences. the guy i bought the engine from was just swapping engines for people on the side, then he'd take the old ones, rebuild them and sell them...since my engine got ruined already, i have to bore it.030 over and rebuild it.

 

I'm guessing this is mainly because of the 1986 Corvette. All convertibles got aluminum heads with center bolts, but apparently most of the earlier production coupes got iron heads with perimeter bolts. All 87 and up Gen I engines should be center bolt, regardless of application.

 

ok that should make it easier to determine the year. this motor was from a camaro so it has iron heads. from what i understand only the corvettes had aluminum heads, but for 2k for a set, its out of my price range (mine have to be rebuilt)

 

But the intake bolt angle never changed on the Vette engines with C/b heads, like it did on the cast iron heads ;post '86 , hence the year break

Crankshaft differences also ; 1 vs 2 pcs RMS block.
Because the 1 pce has a round crank flange ,the counterweight could not be located there as it is on the 2 pce RMS cranks so it was
moved to the flywheel.
GM changed the crank flange bolt pattern so the wrong balance flywheel can not be installed which causes confusion when guys on
here go to bolt their late 305 flywheel onto some '70's 350 they bought from the JY.