I have no other place to turn and you guys collectively seem like you know a hell of alot so I figured that you wouldn't mind answering a few questions. Ok guys this is one of my virgin post on this board but it's still a very serious one so if you dont know please dont reply, with that out of the way here come the questions: first and foremost on my 1990 350 tbi 4x4 silverado i have these bolt ons in this order: gibson exhaust,8.8 plugs wires and ignition msd 6a, intake and hypertech chip, edelbrock cam pn.3702 and intake manifold pn.3704 as part of their little dyno matched promotion; with crower 1.6 ratio roller rockers and here is where my first question comes in, after i put on the manifold/cam/rollers my low-end perf. went out the window, i went from scratching second with 31's(i have witnesses). to having to jerk it around a corner to get ANY thing besides a chirp out of the tires. now granted it did get noticably faster after 60mph but nothing compared to what it took from my low end. When everything is said and done what the heck did I do wrong? Well thats question number one, number 2 is with all the mods listed above do you think it would be a wise investment; horsepower wise to send my prom off to be reprogrammed. the reason i ask about the prom is because from what i understand the tbi computer is only capable of so much and the after market chips only take effect at wot. correct me if im wrong bash or flame me if you dont like my puntuation and capitalization but please lord please answer my burning questions
p.s. this is probably a no-brainer but for comforts sake would true duals make that much of a difference over my cat back to spend the extra 200 bucks. before you answer i already have headers ordered.

 

I would try the stock chip back in and see how it runs. The increased timing from the hypercrap will decrease your low end torque. The cam will affect it to but that is a mild cam and I don't think that is causing your problem. Is that an automatic truck or a 5 speed?

You don't have too much mods to your engine for TBI. You are just getting started . If you read this board a while you will find many with WAY more mods on their TBI system than you. I would not get a custom chip for such a mild system. I think you would be better off with the stock chip and playing with the fuel pressure a little than using an aftermarket chip.

Before investing in a custom chip. Buy yourself a CHEAP laptop off of ebay (386, 486 or slow pentium) and do a search on here for WINALDL which is a computer monitoring/datalogging program and use it on that laptop to monitor your truck and you will have a better idea as to whether a custom chip is needed.

 

I have an 88 with a 350 and before I swapped to carb i had the edelbrock intake and camwith headers and ignition system i had the stock chip in it and it ran fine it did run lean sometimes at wot though, but an adjustable regulator could of sovled that. As for your loss of low end power i think it could be the 1.6 rockers im not sure but i think that would move the power range up more. Mine pulled real hard of the line and even better when i instaled some 4.10 gears with a eaton posi. To answer your question about the exhaust system i think a good 3 inch single will do, if you like the look of duals gowith a single in dual out. Did you get the shorty headers or the full length headers?

 

for brharris thanks ill try the stock chip, and my truck is an auto.
and for fastredtruck i like your name cause my truck is red and shes gettin faster,but anyway i got the edelbrock t.e.s. headers was that a good idea or a mistake?

 

the edelbrocks are pretty cool as long as you are not trying to make a race truck

 

there aint a shot in hell of making this thing a race truck on my budget but, are those a good set of headers, i dont know anyone that has them i thought you may have some input?

 

Edelbrock also has a chip for that cam/intake and good heads. You might try that, as well.

I used that cam in some TBI work and it was fine. Too good down low for me with not enough top end. Sounds like you'll need some work on the fuel and spark maps, as suggested. I think I got 240hp out of that cam with a bit of custom PROM work. Not too bad. Tire smoke at will.