My 83 Trans am with LG4 305 has basically taken a crap. the cam is wiped out pretty bad, lifters are clattering, not spinning. engine smoking. I tried to replace bad lifters and adjust lash on all lifters but that seemed to make things worse.

So heres my idea. I have a 90 Bird parts car here with a L03 305 TBI engine. I am needing to know if I could use the L03 heads on the LG4 block, and can I pull the cam, roller lifters, and pushrods from the L03 and use them on the LG4 block?

I know the LG4 has hydraulic flat tappet cam, and the L03 has hydraulic roller cam. So I'm not sure it the roller cam would be a direct swap on the LG4? If not can I make it work with any modifications.

My only other option is to swap the entire L03 engine into the 83 TA and swap intakes and run a carb on it.

At this point I'm thinking the engine swap would be much easier.

 

Cam: no. Your LG4 is a factory flat tappet cam, the L03 is a factory hydraulic roller. Your LG4 block lacks the provisions to install the factory valve train equipment (retainer spider, cam retainer plate). You would need retro-fit hardware in order to go roller.

The heads are a direct fit. The intake from the LG4 would need slight modification on the center 2 bolt holes on either side (wallow out the bolt holes), as the factory drilled them at slightly different angles on the L03 (all intake bolts are 90 degrees on the LG4, the center 2 on the L03 are 72 degrees, IIRC).


The problem with a wiped cam, is the metal shavings from the cam being wiped has to go somewhere, and that would be down into the oil pan...which would get circulated by the oil pump, through all the oil journals, bearing passages, etc.

If I had to choose between the 2, I would just swap engines.

 

I would recommend rebuilding the LG4 heads, and putting the LO3 shortblock in. You'd get the roller cam, better heads, better pistons (higher compression) and the induction would bolt on directly.

 

Yeah that sounds like a pretty good idea.

 

I used to have an '87 LB9 cam laying around. Let me look and see if I still have it. If I do, it's yours for the shipping - a slight upgrade from the LO3 cam, won't bother your carb operation at all.

 

ha that would be awesome man. I'd really appreciate it.

 

I hate to bust your bubble, but the 1987 LB9 cam and the L03 cam are one in the same.

A Vortec 305/350 truck or a B-Body LT1 cam would be a mild upgrade though.

 

The LO3 cam was a 10088155, which was the same as the 88-89 LB9 cam with an automatic, but not the same as the 87. The 87 LB9 was a 14093643 (M/T and Export), or 14093630 (A/T).

 

Probably doesn't matter, it most likely went out with the cracked '87 block on the scrap yard run in April. Only had it laying around for 6 years. . .

I'll look one more time tonight, though.

 

HGFFRANK

Why don't you just add the 90's TBI system to your trans am? .... I used all 1990 TBI stuff on my ex-LG-4 car and love it. However mine is a L-98 with LO-3 induction.

 

For somebody who's looking for what's "easier", I don't think that's the answer. . .

BTW, the LB9 cam is gone. I have a cam tube leaning against the garage wall, thought it might be in there, but I'm 99.99% sure it was in the junk block when I hauled it away. The other suggestions made are good ones.