I bought a 76 blazer on Saturday and of course the sticker that usually tells the engine size is long gone.

So is there any way to tell if it is a 305 or 350?

Maybe even a 400?

Thanks in advance!!

Get the block ID # and post it. It is on a pad on the block deck surface that sticks out in front of the passenger side head (behind the alternator on your truck). The # will end in three letters, those letters are the important part to ID the motor.

Or just look up the number here: http://www.mortec.com/castnum.htm

Glad someone else asked this, 'cause I just got a truck and was wanting to know *for sure* whether it was the 350 I was told or not ;)

I don't think the 305 was around in '76. I studied the mortec pages that Lloyd posted and only found a couple 305s listed for 76, and I think those are missprints, since they show the same casting number for a 307 or something which has a different bore.

Anyway, it could also be a 400, they have a third freeze plug on them so they are easy to spot. Now if you want to know 2 bolt main vs. 4 bolt main, I have no idea other than looking up the casting numbers.

edit: Just looked again, the only 305 casting number listed for '76 is also listed as the casting number for a 262 which has a different bore. So I'm still convinced it's a misprint.

It could very well be a misprint. However, Chrysler used the same block casting for the 426 and TH413 into the '70s (much different bore). They just left massive thick cylinder walls on the (truck, heavy) 413's. So it could be correct, also.

Block ID # (located as described in my reply above) is a much more exact way of identifying a Chevy engine than casting numbers. Mortec only lists the casting numbers.

Unless of course, in the last 28 years somebodys pulled the motor and replaced it with something that's been decked... Which is highly likely. So go by casting numbers.