Apologies for my ignorance of some basics in advance.

I have a complete customized roadster with fabricated and lots of unknown OEM parts, which do not have identifying marks (hoses, brake components, etc.). I was told the engine is a "305 Trans Am" crate engine. It is mated to an automatic transmission.

Before I go crawling around under the car, can anyone give me some guidance where to look for engine and transmission numbers? I'd like to ID the engine type and more specifically the transmission to determine if it is a 700R4 or another GM transmission.

thanks.

 

Pictures of what you have would help. A chev 305 is a chev 305. Unless it's still original, it's just another 305. Intake swap, cam swap etc doesn't make it a Trans Am engine or even a Corvette engine any more. Crate engine is just a stock replacement engine. Could be any combination of parts or power level.

Transmission could be just about anything however a 700R4 is a good guess. Could also be a simple TH350 if it doesn't have OD on the shifter.

Casting numbers on the block are at the left rear of the flexplate housing behind the driver side head. Production and suffix numbers are stamped on the pad in the block in front of the passenger side head. A crate engine probably won't have anything stamped there since it's not a production engine. Depending on when the block was made, there should be a 5.0L cast into the side of the block if it's a 305.

As for the transmission, take a picture of the oil pan. It won't indicate the year of production but it will help identify what it is.

 

Many thanks!

So what I mostly likely have is a GM 305 crate engine, and the previous owner telling me it was a "305 Trans Am engine" really was just a bunch of marketing BS.

Will get some photos after I get the car jacked up. Will likely be a few weeks before I get time.

Thanks again.

 

The "Trans Am" used the same engine as the Camaro RS and IROC, Firebird Formula, etc. Additionally there are quite a number of different "305 Trans Am" engines - ranging from about 150 HP to 225 HP depending on the year and how it was equipped. Things like the LB9 and L69 aren't likely to be found in "crate" form. Indeed my 91 Formula has a legit GM "crate" engine from 20 years ago - and even at that time the LB9 it originally came with was no longer available in crate form from the GM dealer and so it was replaced with a common L03 - which is just the same 305 used in EVERYTHING from that era. Your typical sedan and light truck engine from the 80's and early 90's having pretty pathetic performance in the grand scheme of the SBC. It's not a bad engine or anything - and when equipped with the N10 exhaust and TPI that's on my Formula I don't think the average driver could tell the difference. The previous owner said they didn't notice a significant change in performance.

GD