Exactly, what does an LB9 engine have that differentiates it from other 305's? My LB9 (87 SFD, 190 hp) has had the TPI replaced with a 650cfm Holley 4777 car on a 14101074 manifold with a 1/2" spacer. What sort of HP would this engine be making, now? Is it good, bad, or UGLY? There has been much carnage to the emissions gear, BTW

 

Probably find more knowledgable people on the 305 on the "3rd Gen Tech" board...... moving post there.

 

Thanks for the guidance!

 

Thats just it, a LB9 is a 305 with TPI, a 305 with a carb was L69, which also had a certain cam also.

 

And a 305 w/ TBI is an LO3. So what differentiates it from other 305's? The intake system, computer/lack of, cam and maybe some more little things.
-Rippin

 

The heads are slightly different, as LO3 TBI has swirlport heads and L69 carb and LB9 TPI have more normal heads. The 5 spd LB9 engines got the L98 cam in them stock.

Basically heads and intake system are the biggest differences.
LO3 had a tiny exhaust compared to the others. All respond similar to mods.

 

Close, there were two carb versions (aside from the crossfire) in the early third gen years (both using a quadrajet) the LG4 (between 145-165hp depending on year) was the base 305 "low output" motor while the L69 was the better carbed version rated at 190hp (slightly underrated).

Although you could get the L69 in '85-'86 it was essentially phased out by the LB9 in '85.
Ironically the L69 could outaccelerate the early LB9s (I know I had an L69 for about 10 years and liked it as much as my LS1). The LO3 did the same to the LG4.

 

I was just using that as an example, just to show the point I was getting at..I didnt even want to get into the TBI 305s