Stock Vortec Rockers?
 

Today I pulled the old 4.3 from my Blazer and installed the reman'd GM longblock I bought. I noticed the rockers on the new engine are different than any I remember seeing. They look similar to LS1 rockers. My stockers look like this:

https://blazerforum.com/forum/attach...ine=1367748423

Which is what pulls up when I search for replacement Vortec rockers. PN 12599650

This is what came on the new long block:

https://blazerforum.com/forum/attach...ine=1367748423

Do those look correct?

After more research, I've yet to see a set of Vortec heads online with the 2nd design rocker arms. Can anyone else confirm that their rockers are similar to the 2nd set I posted?

i have never seen those rockers on any 4.3 that i have looked at.

Really? That makes things just a little more interesting. Thanks!

No one has seen these rockers on a set of Vortec heads?

ive been looking around. closest thing ive found is the rockers off the newer corvettes. Almost looks the same.On yours, strange part is the flat area above the pushrods. all i find is domed.

They look very similar to newer GM LS engine rockers.

Yes, they make improvements as time goes along.What I like about them is that they ride on roller bearings.Unlike the older rocker arms which don`t have bearings at all.Plus the newer one`s are made out of aluminum

2002 and older, ("W" VIN, L35 engine) uses standard rockers. 2003 and newer, ("X" VIN, LU3 engine) uses roller rockers. An easy way to quickly identify an LU3 engine, is that it does not have secondary air or an EGR valve.

My 2001 vin W had roller-fulcrum rockers.

Same roller rockers were used on at least some 4.3's from whenever they switched through 2013 or later - these are the P/N 12599650 rockers.

Looks to me like you have the Melling MR-903 aftermarket rockers, which are supposed to be correct for your engine and application.

Google "MR-903 Photo"

Can't remember if rockers were any different on my GM rebuilt engine but mine was really for the 2002-2003 Blazers if I remember correctly (back-fits 2001).

I wouldn't worry about it. And warranty is excellent on these engines. 3 years/100K. Don't forget to replace your radiator (oil cooler) or your warranty will be void, especially important if you have had bearing failure.

Where did you get it from? I liked Jegs. Good price, no core, free shipping, no tax and I got to keep the shipping crate.