What’s the difference between a 1988 305/TBI from a Camaro vs. one from a truck? Are there any differences (heads, cam, compression etc.)?

 

If the truck is a 350, the fuel injectors will be have a larger flow than the 305 injectors.

 

The 305 in the camaro os an L03 'E' engine code. It is a roller motor which is way better. The truck's 305 L03 is an 'H' engine code. It is a non roller motor and may have a tad less compression due to deeper dished pistons. Most of the newer blocks are machined for roller lifters though, so if you are geting one from a truck to build up, you can make it roller. The former 'H' engine code was the LG4 up to 1987, so don't get one of those(they ere carbed).

 

I got a 1988 305 TBI and the guy I bought it from claim that it was taken out of a Suburban. I have never seen a Suburban with a 305 so I guessed that it was an engine taken from a truck or something. The engine is labelled LO3, 5.0 and Canada (cast on the gearbox flange) and I have no idea of where it came from or its history.

What I would like to know is if there are different versions of the LO3 engine with different components like heads, cams, and compression etc. or if a LO3 engine always is a LO3 and that they are always the same no matter what car it was originally mounted in.

You have to forgive me if this is a stupid question but this is my first experience wit the 305 TBI engine and I am therefore seeking as much information as I can about it...

Thankful for any help / Robert

 

as far as I know they are the same except....like I mentioned before, the H code was in trucks only and it is for sure a non roller motor. They two engines (E & H) have very similar cam grinds, if not the same. As far as I know the heads are the same. They have 58cc combustion chambers. They only internal thing that I know might be different is the dish size of the pistons. If this is true, the truck will have slightly less compression than the camaros. I can't honestly say for sure though, but it will be at least a 9:1 motor anyway in '88. So to anwer your question, no, an L03 isn't just an L03. Another example of this from GM is the LB9. It is the TPI 305 'F' engine code. However, depending on whether r not it was in a 5 speed or automatic, it had either 230hp ina 5 speed, or 205hp or 190hp in an auto depending on the year. The main difference there was the cam specs.

 

How do I identify the engine as an ‘E’ or ‘H’? Do I have to open it up to check the pistons etc. or is there any other easy trick to identify them. I don’t have the VIN and it is really hard to read any of the stamped numbers of the engine

 

Thanks a lot for your help TBIWorks. The engine is newly rebuilt with ported and polished heads but with stock rods and pistons (I have to check them out somehow). It also has a Comp Cams Extreme Energy cam and the block was checked for cracks and the crank had a regrind etc. Intake manifold and TBI looks stock to me but has an adjustable fuel pressure regulator.

I just don’t know the potential of this engine and I cant make up my mind if I should get rid of it as soon as possible or if I should keep it for a while and continue to build on it?

/ Rob

 

well, is the motor intact? if the intake is on pull it off and a roller motor will have a spyder retainer looking thing in the lifter valley. It has arms that reach to the lifters and hold them in place. If it is has this, then it must be an 'E' code from a GM car. However, if it doesn't have this retainer it is an 'H' code from a truck. When you pull the intake manifold off, it will just have pushrods to lifters, and no retainer. This is only if the motor is intact. If someone has messed with it, then you better pull one of the lifters out to make certain whether is is flat tappet or roller. One thing that you need to do to identify it as a later model motor is look to see if the bolts for the valve covers in the heads are center bolt. If they are not, then it is an '86 or older. Finally, make sure it has the holes in the center of the lifter valley machined for the roller retainer, even if it isn't a roller motor. All the later model blocks are machined this way, so if you rebuild it, you can make it roller if it wasn't already. Hope this helps

 

Did you read my last post? I posted it in reply to your question, but you appeared to have posted before I did. Yeah, if it is done that way, then why not build it. One thing, if it had an adjustable fpr, it might have been from an f-body cause people usually try to supe them up.

 

So what you are saying is that the main difference between the 'E' and 'H' codes are pistons, rollers and cam. My 305 already has a new cam but chances are that it has the 'H' pistons and no rollers, right?

This will help me a lot to make up my mind about what to do with the engine. I think I have to mount it in the car and get a feel for how it performs in its current state before I make the final decision. I could keep most of it and rebuild it again or exchange it with a 350. Future will tell…

Thanks again for enlighten me

 

Looks like we are "cross posting"

I think it came from a truck because I found it in a truck. The engine and gearbox has been beefed up because the truck was used for some street racing before the previous owner lost interest in it in favour of a twin turbo LT1.

I will stick with this 305 because I have to and later on decide if I should continue build on it or if I should exchange it for a 350. It will all depend on how it performs and what usable parts I might find. The motor got centre bolt valve covers by the way...

/ Rob