I have a 2001 Jimmy and I just replaced the spider injector set up with the injectors at the ends of the legs instead of poppet valves. I was wondering how easy it would be to upgrade the injectors at a later date or if i would have to replace the entire system again?
Also was wondering if anyone has used a Hypertech III system to tune or anything on their 4.3?

 

To my understanding the spiders are not able to be upgraded. Wynjammer has spider that has been beefed up to 36lbs per hour. Another option is the marine intake which has the "normal" top feed injectors on the out side of the manifolds.

 

Upgrading lb'dage means you HAVE to upgrade your motor.. The 4.3's are only rated for so much... And you CAN upgrade injectors from a diff motor.. I believe.. with a new PCM, ecu, etc.. w/e you wanna call it.. For a re-flash tune and program.

 

Yes.. and no. You dont need more delivery capacity until you get to significant forced induction

4.3 stock long block can easily handle 10% power increase. It's a CSB for crying out loud!
4.3L Vortec Marine Intake Conversion Helpfull Hints:

 

The bottom end on a 4.3 is good for 350HP. If you can upgrade JUST the fuel delivery to get that from 190 stock HP - SELL the secret!!!
Yes about Wynjammer & Yes about a marine intake upgrade. My intake came with 33lb/hr Bosch injectors. The wynjammer caused the stock spider assy. to lean the engine out around 4200rpm, not the case with the marine intake & Bosch injectors. But a stock engine or naturally asperated engine without a HUGE cam swap wouldn't benifit from more fuel delivery. IMO

As for Hypertech III do a search & it'll turn up lots of reading.