I bought a 87 Firebird with an H engine code in the VIN. It has never run right and wonder how to ID the engine? It has a Holy carb but is it comparable with the engine?

 

H was the LG4; the base 4-bbl carb setup.

The OE carb would have been the computer-controlled Q-Jet.

Not sure about a "Holy" carb; but if it's a Holley, then somebody has had their d***-skinners in there. As far as "comparable", that would depend on the particular carb; and how good of a job they did installing it. For example, did they put in a distributor with vacuum advance, did they get the TV cable geometry right, and so on.

Of course it's also possible that there's some complete other engine in it now. Might not be a bad idea to post up the block and head casting numbers. Block # is conveniently located in one of the most accessible places on the whole motor: top of the bell housing flange, behind the driver's side head.



Head casting #s are in between the rocker arms.

People will tell you to look at the "stamping" code on the pass side deck in front of the pass side head. Don't bother. AT BEST, that will only tell you what application THE BLOCK came from, IF you can even find it listed online somewhere. (some of the older ones can be found). Won't tell you what THE MOTOR is, except that it's a good clue as to the displacement (305 vs 350). Look at the casting #s instead.

 

I am told it ran well before going into storage. First thing is to see if it runs. Replace fuel tank and fuel lines to carb. If it works fine, though that check engine light will come on. Any advantage to original equipment?