Chevy engine ID?? 305 or 350??

[WishinIWuzFishin]

Just bought a 1985 Chevy 1 ton van. Need to do some tune-up work and trying to figure out what engine I have. According to label under hood its a 305, but from VIN code deciphering charts I found, it's a 350.

Anybody know an easy way to tell the difference. Or does anyone know where the engine ID numbers are stamped?

Thanks in advance.

[Bonecrusher]

Should be right underneath the cylinder cap. They basicly use the same parts for tune-ups. The major difference between the 305/350 is in the cylinder heads.

[T-180]

A 1 ton van should have a 350 in it. It's possible that the wrong label was put on, either at the factory or at a body shop when it got repaired.

[wave warrior]

if its original engine id say 350...dont think they ever used the 305 in a 1 ton...and for an 85 the tune up kit is the same,plugs.wires cap n rotor,filters pvc etc!

[jason454ci]

I would go off of what the vin number says it is. All to often parts get changed and the label is off another vehicle. There is casting numbers on the back of the block by the bell housing that you could find to be sure. But as far as tune up parts everything would be the same with the possible exception of spark plugs.

[The Big Ugly]

Since its in a van and you are going to have the dog house off to do a tune up, just look behind the distibutor near the bellhousing on the block. there will be 5.0 cast into the block if it is a 305 or 5.7 cast into the block if it is a 350. it may be covered in sludge.

[WishinIWuzFishin]

Thanks for all the replies. It never even occurred to me that the tune-up parts would be the same for both. I just wanted to be prepared when I go to the parts store and the guy asks "what engine" ....I didn't want to look like an idiot and reply...."gee I don't now for sure".

I found an old Haynes manual I have and it shows where the engine ID numbers are, but now I can't find anything online on how to decipher them. I found on online decipherer for the VIN number.


To the big ugly: That's the first I've ever heard of that number. Will be looking for it when I take the doghouse off.

I think I'm just hoping it's a 350. Had 2 vans before with 350's and loved both. Had an Olds 88 with a 305 and didn't really like that motor.

[BIGDADDYDB]

I'm not sure about the older ones but lift the hood and look for the plaque on the front edge that has a picture of the fan belt and pullys. On that plaque it will say the displacement 5.0=305 5.7=350

[jason454ci]

Once you find your casting numbers on the back of the block you can use this site to figure it out.

http://www.nastyz28.com/sbchevy/sblock.php

Good luck with finding 5.0 or 5.7 stamped on it. Some of the newer ones may have it on it but not the old ones.

[Searay]

Should be right underneath the cylinder cap. They basicly use the same parts for tune-ups. The major difference between the 305/350 is in the cylinder heads.

Also 305 bore 3 3/4"...
350 bore 4"

[dinkbuster1]

i am pretty sure a 350 uses a different size ignition module, coil, and know for sure a bigger starter than a 305. other than that everything else is the same.

[JIG]

Look the same but Pistons,crank,rods,heads and valves are diff. 350 used 1.94/1.5in. valves an 305 used 1.8/1.5in valves. Diff bore an stroke also. They had ALOT of valve train prob. with them. The gutless wonder 305!!!!! Chevy thought they had a good smog motor but turned bad.