I don't know if they're vortex, or what that means, but they were used on 305's and 350's, '87 and up, and they have 1.94 intakes and 1.50 exhausts.
No they aren't. They are 1987 TBI heads
Actual olds heads casting numbers are underneath the valve covers
1996 Trucks but not all, look for casting numbers 062 or 960 on the heads
It is stamped into the top of the heads where the valve springs are.
This number will tell you what year and what moter the heads will fit.There are books put out for this purpose.
read casting numbers and research on the web. Just Google small block Chevy heads castine numbers. These numbers are under the valve covers so you will have to take one off.
Those may not be the numbers needed for correct identification. I've seen that 3970010 on many, many blocks. The block number you need is usually stamped into a small id plate just ahead of the right cylinder head. The head numbers are under the rocker covers, and can be difficult to read if they are covered in sludge, which is common. With the correct numbers, you could go to a website such as: http://www.auto-ware.com/techref/castnum.htm to answer your question.
Chevrolet L99 "baby LT1" 4.3 liter 265cid V8 cast Iron heads from a '92-'96 caprice or impala
Find a book on casting numbers for chevys it will give you the year of the block the heads & the manifolds.
They are basically the same heads, If the 93 350 is a vortex motor.
they came with "186" casting number heads.........
It's hard to say they made different castings on the (double hump) heads but GM claimed from 300hp to 375hp for the 327 depending on the heads you should run the casting numbers to find out exactly what you have
The combustion chamber size of the heads with the casting number 376450 is 60cc. It is possible to install larger valves.