Hey there everyone.

I'm mostly new to this whole forum thing, but I figured it would be the ideal spot to get some answers since I've seen quite a few already on here.

I had done a 4.3 swap on my blazer to replace the old original one, but the one I bought to replace it was originally out of a 1500 Silverado. I rebuilt the one that came from the Silverado with the parts needed that came from the blazer, in addition to redoing the gaskets down to the head and oil pan. I've listened to many different blazers on stock exhausts, like mine, but mine still seemed a bit louder with a tougher idle. Almost as if it were cammed differently. This leading to my question: Were the s10's 4.3's cammed differently compared to the Silverado 4.3's? Would anyone happen to know the answer?

 

What years are we talking about?

 

The blazer is an '01, but I believe the engine pulled from the Silverado is something of an '02 or an '03.

 

So there is specifics, but I believe its more to the injection system... I have a 99 and replaced the engine. I used an 03 engine but had to keep my manifold do to specific connections...

If you do a quick search on engine compatibility, it'll tell you what specific injections they have one the 3 engines I believe...

Edit:

Here's where i was looking for help. Les makes a good point on the engines in this post.

As you have an 02, it relates to your engine as well.

https://blazerforum.com/forum/engine-transmission-35/engine-differences-101640/

 

Would you think that switching to the MPFI spider replacement would have anything to do with that? When I rebuilt the engine I had to replace the spider, which was originally Sequential. Never touched the ECU, so maybe the sequential tune was intended to run more fuel?

 

Thank you very much. This helped a bunch. very appreciated.

 

No problem. Let us know if you get the problem figured out!