Don_89Iroc

how can you tell a 85-91 305 TPI car from a 350 TPI car, can you tell bye just looking at the motor or do you have to have the vin number??? im asking because my car is a 5.7 TPI and his T/A is a 305 and the A/C and the alternator are on different sides on his car than mine and he says that some 350's have the A/C on the same side as his car does thanx for your help

RedFirebird

No, the only way to differentiate between the two engines via the eighth digit of the VIN number, besides crawling under their and getting the casting numbers off the block or the heads. This is if the engine is stock of course. If its an L98 (350), it will be an "8". If its an LB9(305), it will be an "F". The location of the A/C compressor won't tell you because all f-bodies had the A/C compressor relocated to the passenger side i believe in 87 or 88 to "unclutter" the engine bay (didn't work).

BobbyK

Didn't the connections to the fuel rails differ.Wasn't the 350's fuel rail connection point on the passenger side of the eng. and the 305's connection point went from the passenger side down and across toward the drivers side of the block?

whiteroc

The only differing TPI fuel rail set-up would have been with the Corvette. The 305 and 350's external engine parts were all the same except for the injector sizes and a different knock sensor.
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Besides the VIN"8"&"F", you can tell the size of the original motor by the sticker under the original hood - will read either 5.0 or 5.7.

Frank88

I resolved this question on my car (which although it came with a 305 supposedly had been swapped out for a 350) by pulling the driver side valve cover and reading the head casting number. Mine is a 350! Confirmed by injector part # also, although these are very difficult to read.

350 = 14101083

JWZ28

I pulled an 87 TPI motor out of an 80 Cutlass and saw on the back of the block a casting mark which read '5.7'. That's pretty hard to say it's not a 350 motor! HTH

360Iroc

you know some people use 305 injectors on 350's

bigals87z28

hey another way is that if u look under the glove box cover u will see a sticker with all the RPO codes u can look for LB9 or L98 i always wanted to know what they put in my car.. my dad said that some time after he bought the car he found there was a crack in the block... but it was covered by waranty but maybe just maybe they mixed it up and didnt put a 305 back in but put in a 350!! nahh couldnt get that lucky... maybe.... hehehe