GM 60 Degree V6 Power Tips/Mods
(Return to Troopers.)
Go to this link: [ http://www.4x4wire.com/tech/60degreeV6/]
4.3L TBI conversion:
Ed Mc. said: Looks like that would do the trick! Note that since this is a 'later' model TBI it probably has a different T.P.S. plug than yours. No big problem there, you can go to a wrecking yard and find an S-10 or other TBI'd GM vehicle with the same type of plug on its wiring harness. Cut that plug out and splice into your harness. Or, I believe you can also switch over your old T.P.S. to the 4.3 TBI.
You won't need a different fuel pressure regulator, even the stock one is adjustable. Probably won't need to do that, either, although unless you have modified your 2.8 with other airflow-enhancing improvement the 4.3 injectors will be too rich. Just switch out the 4.3 injectors for the injectors in your 2.8 TBI.
Don't forget that to use the 4.3 TBI atop a 2.8 manifold you'll need to bore the intake; otherwise the throttle plates will hit. Only other solutions would be to use a 3/4"-1" TBI spacer plate or the adapter gasket Holley sells for their 502-3 Big Bore replacement TBI. P/N of the gasket is 508-7.
http://www.holley.com/508-7.asp
Note that you won't achieve anywhere near the performance boost possible with the larger TBI unless you bore the stock intake.
Here's a bunch of good info on this mod in case you haven't seen it already:
http://www.4x4wire.com/tech/60degreeV6/
http://members.shaw.ca/betterthanyoutoo/how-to/28to43tb/28to43.htm
http://forums.s-series.org/viewtopic.php?t=15211&highlight=replacing+2+8+tbi+4+3
After you complete the installation, don't forget to adjust minimum idle speed and T.P.S. voltage. Otherwise it'll run funny, surge and die out.
Here's info on that procedure:
http://www.4x4wire.com/forums/showflat.php?Cat=&Number=445449
http://www.s-series.org/htm/how2/tpsadjust.htm
Reference: research papers
