I had a guy put a 350 in my '89 RS last year.
Was a 305.
Is there a number on the engine which will
indicate what vehicle it was originally in?
Thanks!
Chuck

 

Closest I can think of is the block casting number. Imprinted behind the driverside head on the block. Might have to rub a little cleaner it if it's really hard to see.

Here's a list I googled. I'm not positive if all the numbers are correct or if the info is totally correct on the page.

http://www.classictruckshop.com/castgm_smblock.asp

 

Look at the front, on the machined 'pad' right infront of the pass. side head. There will be numbers and letters machined into that spot if it came in a vehicle (none if a crate motor)

Now... there are 2 rows of numbers/letters. IIRC, the upper row will tell you what the original engine combo was (ie. 454ci-250hp or something) and what kind of vehicle it came in (full size, truck, etc).

The lower row will have the last bunch of numbers from the original vehicle's VIN number.

If you post the numbers/letters here, someone will be able yo decode it for you and tell you what it all means.