is there a difference between L03 and a LB9 the casting only
because i bring my blown LB9 to rebuilt shop and they gave me back a rebuilt L03 and i put all the tpi stuff on it and i just remarked that the code in the back on the engine is gm5.0L LG
LO38 ??? same block exept the cam or something else different?

 

same engine, different choice of parts

 

The shortblock, as far as I know, is the same. The induction (TPI vs TBI), cam and the heads are whats different.

 

thank you. there is no difference in the block casting exept the cam, heads and tpi intake and plenum. only that makes that much more HP?
T5 (manual) LG4 9.3:1 305 170@4400 250@2800 4bbl 3.23

T5 (manual) L03 9.3:1 305 170@4400 255@2400 TBI 3.08

T5 (manual) LB9* 9.3:1 305 230@4600 300@3200 TPI 3.45**

wow!

 

I believe the lb9 is also a 350

 

not really 305 is LB9 and 350 is L98

 

oh my bad.

 

how about the gm crate engines ..lo3-e ....is this the replacement of the lb9 ?

 

To my knowlege there is no direct crate motor replacement for the LB9 or the L98. TBI engines all had swirl port heads, TPI engines were all standard non-swirl ports. And in most cases the TPI engines used a different cam (the 305 TPI with automatic trans used the same cam as the L03 from 87 thru ~90 but that's the only applications they shared the same cam).

 

Virtually nothing matters about the block, just what gets stuck in it. The cam makes a big difference but it's also got 20+ degrees more duration as well. If it's an N10 (dual cat) car it's got a superior exhaust as well which is a big thing on these cars. They were sort of (really) lousy from the factory in the exhaust category.

 

The L03 heads were awful and the cam was awful. The LB9 got decent heads and a decent cam, and maybe a slightly better exhaust - that's where the differences are.

 

keep the lb9 081 heads and camshaft and buy a roller cam 350 and injectors... dont waste $$$ on a 305 crate?!?

 

but check this out....... http://www.crateenginedepot.com/stor...-P786C273.aspx

tell me if there are misleading us ........................

 

in my first post 7 years ago my l03 last a week..then i remplace it with a 1974 rebuilted 350 with ALL THE 305 stuff but you need larger injector the 19 lbs are to small...if you waste 2000$ on a 305...you are crazy...i remplace my 350/305 heads for a LT1 because the tpi kills the high end rpm.. and i picked a to wild cam and i had major problem with www.lt1intakes.com...

 

i am just trying to find a replacement for my 305 tpi 1988 iroc convertible i have enough speeding tickets ......... engine has just over 100,000 miles and i feel a lost of power in it

 

Lq4 (pick up engines)lt1(trans am,camaro,corvette,caprice) will fit with adapter plates(ls-lq) and wire harness...

but any ROLLER CAM OLD 350 at the junkyard with 8 24lbs injector would be your best choice...305 heads on a 350 with a low duration cam works good forget the crate 305 its a total waste of $$$ for less than 200hp!
true direct bolt on...the non roller cam block will need a diferent flexplate.

 

They are misleading you. That's a TBI (swirl port head) engine.

 

?!? 081 lb9 heads will bolt to any 350 except lt1-lt4 ls1 where am i miss leading

 

not you ....crate engine depot.....................look at the link

GM Performance 12518296 - GM Performance 5.0L LO3-E Chevy Long Block Assemblies

......... drop in replacement for iroc-z 305 ....................its a lo3-e not a truck engine