When we started this change over truck had a Phatom Grill and a lot of custom work and only a 4.3 z motor, TBI ECU is listed as: Service # 16168625 BBMW 86BBMWK330491987, reference info if needed.

Did not know and was not told a B.B. TBI was an option, but Turbo City did say they could modify TBI sticks a little when pushing on it though. ANYWAY, we had hoped to build this 5.7 4 bolt main with 2.02-1.60 Pro 67 Torker Heads, which instead we got stuck with 76 cc heads as stock SR told they were Torker's, 1.94-1.5 valves, with F.M. H345NP40 pistons. Comp Cam 212-218 444 lift, Rocker 1.6 Rollers. Balanced, after ARP rod bolts and resizing rods, but We use TBI manifold from Edelbrock 3701, which I am selling now. I got maker of heads to replace heads and promised to ship them immediately, which they did ship BARE heads.

We are re-considering since disabled, to use 76 cc heads with .015 gaskets and shaving heads .020 to up compression for now. NO smog, but we were not sure about EGR and ECM after we change out all MAP, Knock etc to 5.7 and it seemed to run rich. "Custom Chip" Turbo made and PROM from GMC matched to truck except 5.7 not 4.3 all ran very rich, enough to put a black ring on ground, waste gas etc. WE notice a little white smoke after black smoked cleared after awhilel and became worried about leak and pulled heads off when I found cc issue as when sick I did not put together and stock heads, which suck as I had these already with valve job and double springs etc. ANYWAY, sorry little frustrated, we had a heck of a time pulling one head from carbon, I assume, was build up in heads and on top of pistons 9800 miles only, moly rings and HYP pistons seems in good shape otherwise. Compression on gauge before it broke was only 122-125 but steady on all cylinders, we assumed another reason to check motor as vaccum seem to drop from 15 lbs to 12 at idle we assumed low compression, cam and vaccum was throwing computer into thinking it was under a load thus fuel problems etc. After pulling heads maybe wondering if other issues as carbon was terrible, took pictures before and after cleaning build up on piston's top and head chambers etc.

WE have been looking at winALDL, TCCat sites etc on how to make our own chip after the not so great experience so far. We also were told a injector spacer such as cfm-tech.com would allow TBI to pull air from either side, never liked 180 manifolds, injector spacer may up Turbo's modified TBI that is suppose to be 590 CFM some to say 600 CFM, which we use to run a 650 carb on a 350 plus Pontiac 400, it seemed ok.

Can you use and tune TBI's to run better and allow more cam options then stock cams as Some TBI cams suck, in my opion. I was told a 112-114 CL was needed and no more then 210 duration, would of liked a little more duration and around 480 of so lift, hydraulic, as changing cams is less expensive this way for now. Later, we hoped to go to a 383, but health and wrong heads held me up. We wrote Pro about heads as they were to replace 217s sold to us as 67 cc torkers, but with out valve etc, cost is more then I have right now as I try to fix truck to move out of filed before bad weather, tornadoes etc in OK come.

I also have the 4L60E transmission which is in good shape, but we had hoped a TBI system could be modified to run and with a little better cam choices then performer cams etc without thowing computer into thinking it's under a load. I was tempted to get 750 Holley and Dominator down the street for 125.00, but I am told TBI's can get better mileage and work better then mine has so far and asking for any help in this area and if it's possible? :hail: Help as I try to catch up with new technology and gain HP. For the records, it's ran rich and little white smoked when black smoke cleared showed up after 3000 mile drive across US very light but a concern, MANIFOLD GASKET? 65 Police injectors! (Tach is off about 25% from change over from 4.3-5.7!)

 

I have learned the hard way to keep it simple and not stray too far from stock when dealing with GM"s TBI and computer. There are a few guys on here that can stray a little further by burning their own chips but i am not one of them.

 

Dont get a carb. Your setup is definatly tunable with a little effort. You do need to get into doing your own tuning, though. Go over to the DIY-Prom board and there are guys over there who are using the same pcm you are and they can help you tune it. Do some searches and youll also find some links to other boards that have even more people on them who know how to tune with those pcms.

 

Thanks, I did look around that site, tried tccat, winaldlhttp://www.winaldl.webhop.net/ and I was hoping that is true and hate to give up now!

I did post a question at site (DIY-Prom) you mentioned and hoping, while I try to figure out how to post pickup. I appreciate the encouragement and needed it as it can be costly and frustrating if you go the wrong direction.