Hey everyone I'm new here and lovin the forum. Well I decided to make a post here well I just bought a 83 trans am. For a project car for my high school Auto shop class. I changed the oil and put fresh gas in it cause the guy I bought it from said it had been sitting for about 2 years and I got it to start to get it on the car dolly to get it home. Well he said it has a 350 in it(he bought it like that he didn't put the motor in himself) and the stock car with the vin said the car came with an LG4 305. and I've checked the heads and they are 350 heads so im not sure if its a 305 with 350 heads or a 350. I was told if the cars slugish at first in the rpm range it's prob. a 305 with 350 heads but the car runs really strong through out the rpm band. So I am going to try pull some numbers off the block if I can get to them.

So my ? is how much faster would a basic 350 be compaired to a stock 305. like 1/4 mile time and such? and anyother ways to tail if the block a 350 without pullin the numbers. also Shouldn't the numbers be on the back of the block on the drivers side?

Thanks For the help and Great forum!

 

There are lots of really strong 305s out there, and alot of lame 350s. Seat of the pants is a bad way to attempt to figure out what you have.

Look on the bellhousing flange, directly behind/below the drivers side cylinder head. You'll find a casting number there. Read that number (the last 3 digits are really all you need) and look up that casting number here

MorTec, Inc. Home Page

They have a listing of blocks and cylinder heads, by casting number, with some details on what it is. If you can't find what you are looking for there, post it here and we can help you too.

Good luck!

 

see what size of chambers those 350 heads have, if it's a larger chamber then it's almost definetly a 350. A 305 with big chamber 350 heads will have horribly low compression and should be a dog all around. You can also run the block numbers but they can be a real pain to make out especially if the motor's old and oily. Time for a round of routine maintenance, and make sure everything's set right, if the motor's healthy I'm sure you'll be happy with it.

 

yeah its really dirty and I cant really even see back behind the head. But thanks for the help I will probly sometime try to get back there and clean off the back of the motor and try to get to the number. Thanks again and Im sure Ill be back with somemore Questions.

 

Which side of the block is the dipstick on? That won't tell you if its a 305 or 350, but it could help to figure out if its the original motor or not. If its on the drivers side, then its a pre-1980 block, and definitely not stock, and a good possibility its a 350. If its on the passenger side, then it could be the stock engine, or a 1980+ block thats been installed.

 

Good choice for car to restore!
I'm liking it.

 

I think you have an f22 or maybe a b16..... I'm just kidding, anyway shouldn't the block have it stamped on the back, on top of the flywheel, maybe you can shove a mirror back there and see, my 88 iroc had 5.0 stamped back there

 

Ill look and see. And yeah the dip stick is on the passenger side. Thanks guys and yeah Im really enjoying this car its fun to work on and enough power to keep me happy.

 

Look for a pad in front of the passenger side head it should have 3 letters at the end of the sequence that is the suffix code you can look up the suffix code at Chevymania! that will tell you the exact year of your engine HP and everything.

 

cant figure it out I pulled the suffix number and its (v1118ddn) whats my motor thanks for the help every one!!!
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found it ddn is the 305 LG4 so I have a 305 lg4 with 350 heads thanks every one!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!