i was hopeing someone could help me here, i have and lg4 in my 84 trans am, would it look the same as an lg4 from and 87 trans am? the reason i am asking is because at the junkyard there is a trans am that says it has a 305, but the dealer says its a 350 and not the original engine, i am skeptical however, it is carburated, and looks to be in good shape but i suspect he is trying to fool me.can anyone post a pic of an 87 lg4 or tell me how i can better tell the diffference? i could possible buy it even if its a 305, i would get like 20 more hp out of the 87 lg4 right? well anyway if you can help me it will be appreciated

 

Physically, you cannot tell the differance between a 305 and a 350. As for the 87-up engines, they are roller camed, use a different intake/head bolt design, and are center-bolt valve covers. This would be an easy way to tell if its an 87 or newer engine, but still wont tell you if its a 305 or 350. Yet again, someone could use the 87 and newer block, with the 86 and older head/intake combo. In order to be sure about 305 or 350, you will have to get the numbers off the block, and check it against www.mortec.com .

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Rob
'86 TA 305 TPI
Gutted MAF, Ported Plenum
TB Bypass, Home made Cold Air Intake,
Edelbrock T.E.S.

 

The blocks are different. Try to get the # off the block and use that to verify.

 

Yup, casting numbers off the block is the only way to tell with certainty. And even then, that will only tell you the bore; if it turns out that it's a 4" bore block, then it could be a 302, 327, 350, or 377 (or 383 if it's .030" over). Most likely it would be a 350, but again, that's not certain.

If the numbers on the block show that it's a 305 block, then the dealer is lying just to get the car to sell faster or for more money. I can't believe that a used car dealer would ever do that though, that's never ever happened in the whole history of that business. That's why those people have such a sterling reputation for honesty, integrity, and thorough factual research on their inventory. In fact isn't it considered a compliment to someone's character and ethics to compare them to a used car dealer?

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"So many Mustangs, so little time..."
ICON Motorsports

 

what's up with rebuilding or stroking your engine?

 

Well i went and looked at it today, i got a number fron right under the carb and i dont know if its the right number or not it is CFR 17084735 then under it were 2 nmore 3 digit numbers 234 63N can anyone help me tell what this is?? it also appears to have been messed with, it says firebird on the side and the VIN says its a firebird but the back and the pocket on the inside say trans am

 

You need the numbers off of the back drivers side of the block where it bolts to the trans . A very good possibility if it is a 87+ block it might be stamped 350 or 5.7 in the front. I cant remember for sure which side but its in the vecinity of the fuel pump location on the block since its a newer block it should be realivly easy to see. its in small print about 2in back.
SSC
Oh a dealer told me that my lg4 was a 350 since he thought the engine was blown and I knew it wasent I dident bother to tell him to shove it. Also my buddy was told by a "reputable dealer" that his 86 firebird was a 350 BC it had tbi. Oh the humanity.