whats up got a quick question about a engine. I bought a 1986 camaro formerly tbi 305 been switched for a 350 TPI . I took the valve covers and checked the serial on it its 14102191 but the block says
5.7 LG/SGI so its a 5.7 but the heads come back as 305 heads ,what gives?also it spitting out the code 34 so I unplugged the maf and no its giving code 33 does this mean the maf is bad?

 

Welcome aboard thirdgen.org.

What gives is that "1986", "TBI", and "5.7" never went together in f-bodies. Furthermore, "1986" and "5.7" never went together, nor did "1986" and "TBI". And, "TBI" and "5.7" never went together. For that matter, neither did "1986", "TPI", and "5.7". Nor did "5.7" and "191" heads.

So, this car has been pieced together from parts that never went together originally.

 

Like i said in my original post the engine and harness and TPI setup came from a diffrent and newer car just wanted to know why the heads had a 305 casting number yet the block says 5.7. I understand the TPI 350 was found in 87 and up f-bodies and tbi is a whole diffrent set up. just wanted to know about the 305 head casting and the 5.7 block thanks though.

 

Somebody threw them on there for a cheap bump in the compression ratio.

 

It's a Chevy. All that stuff interchanges. Bolts right up.

Somebody just stuck those garbage 305 heads (TBI swirl-ports) on a 350. They fit right on a 350, same as any other SBC heads would. Probably wasn't a conscious effort on anybody's part to accomplish ANYTHING, in terms of "design"; more likely, that's what they had at hand, or could come up with quick and cheap. Or, they took their GOOD heads to the machine shop, and got a "smoking" deal on that other trash, and didn't know any better. Kind of like back in the 70s when people would be working on a 69 or 70 car, and they'd need a valve job; and without realizing it, would drop off their 186 double-humps and bring back a pair of 882s.... somebody would tell them "all 350 heads are the same" or whatever, maybe even stick 2.02" intakes in them and tell them they were "performance" heads now. And then they'd wonder why their car never ran as good, ever again.

See my signature for help in understanding why stupid things happen.

 

Actually, you didn't say that. You did indicate the car was originally TBI, which is was not.

But, the answer lies in the original response - somebody pieced together parts than never came together.

"Why" is a whole 'nuther question, and one none of us could possibly answer.