Does anyone know what the specific difference was between the "W" code and "Z" code engines from 1996-1999? I have a 1996 "W" code and it had only 165-170hp versus the 190hp of the more common "Z" code vehicles. I drove a "Z" code Blazer recently and the performance difference felt like a lot more than 15hp, and the lack of spunk in my Blazer is getting a little annoying. I was told that the main difference between the two had something to do with the type of fuel injection they used. The question is, what is the difference and is there any way I can switch what I have?

 

I think you mean VIN 'X'. The VIN 'Z' reference goes back to the TBI motor when the VIN 'W' (RPO L35) was the CPI motor (1992-1995).

The difference between the VIN 'W' (RPO L35) and VIN 'X' (RPO LF6) is likely programming only.

I believe the LF6 was rated at 175/180 HP, 240/245 LBFT when in a 2WD/4WD respectively. The L35 was rated 180/190 HP, 245/250 LBFT when in a 2WD/4WD respectively. Now, those numbers are for the pickups. As far as I can tell, the L35 was the only engine option for the Blazers from '96 until mid '03 when the motor was updated (egr system & injection system most noteably). Take a look at your RPO code listing for confirmation of the engine you have.

 

I don't know what the RPO is. I have the original window sticker for the truck and it does say that it's SFI rather than CPI.

 

If it is '96+, then it won't be CPI. Check the RPO code list on the label located on the inside of the glovebox door.

 

I checked today. The RPO was L35, which would mean I do have the 190hp engine right? The other Blazer I drove was a stock '94 with the 190hp engine and it took off like a bat out of hell. I realize that the second generation trucks were about 800lbs heavier, but should it really be that big of a difference?

 

800lbs is a lot of weight comparatively. The older CPI engines had more torque down low than the newer SCFI motor due to the long runner intake system. They ran out of breath up high in the RPM range sooner than the SCFI motor though.

You also have to look at gearing when comparing vehicles. A vehicle with 3.73:1 gears will feel a LOT faster than one with 3.08:1 comparing otherwise 'identical' vehicles.

 

What is the difference from a 95 - Z engine out of a van and the W - engine in my 96? I dropped a rod thru the oil pan and I found a Z engine for dirt cheap. Can I swap them?

 

CPI vs SCFI...

 

Can I make the CPI an SCFI? Sorry, I don't mean to hijack this thread.