My Blazer has a 4.3l i have no clue if its a vortech or not.
Its a 91 is there a vin code that will tell me if it is or not?

 

if it's a 4.3, it's a vortech.

 

if it was a vortec it would say it somewhere in the eng comp...

 

Not necessarily... The 'vortec' head design came into play in the late 80's. It wasn't put into marketing use until the CPI motor was put into use.

 

yea im just not sure i know there were some blazer-s10's with the vortech and some with just the reg 4.3l
im just wondering if the vin would tell me...saves time lol

 

I think that there actually is a difference. We have a 4.3 out of an Astro van sitting around, and the intake looks a bit different. Plus the Vortechs usually display the name across the top the intake manifold. Or maybe they are all actually Vortechs and some of them are just high-output models. Either way, I know there are two different 4.3s.

 

Here's a very good timeline history of the Blazer and its engines. In summary, any 4.3L V6 after (I believe) '86 is a Vortec engine. It is just a name applied to the engines that use the head and pistondesign to help create the 'swirl' pattern to the air/fuel mixture. Some plenums had the word 'Vortec' on them, some did not. I thinkthat happened sometime in the early '90's when GM changed the plenum shape to also help with the intake mixture. The later intakes did not have the word 'Vortec' on the top, but they were still the same engine.

 

There are many different 4.3L engines. Some have balance shafts, some do not. There is the TBI motor, the CPI motor, the SCFI (CSFI) motor, and the newest rendition, the MFI motor. The head design is what makes the motor a vortec. And as I stated, the head design came into play in the mid-80's with the first 4.3L engines.

 

1989-1992 - 4.3L Vortec 4300 V6, TBI, 160hp (119kW)/230ft·lbff (312N·m) (VIN Z)

there you go, its a vortec.

 

True, Kyle, therewere many production modifications to the engine during its life, but it was still the same engine. I think what is confusing some folks is the term "Vortec' as applied to the engine (which was not the only GM engine the name wasassociated with). As we have both pointed out, it was the head and piston top design, and later in combination with the redesigned plenum, thatgot the 'Vortec' name applied to it. All the 4.3'swere called Vortec.