hey,

i have currently been trying to afford a powerstroke or cummins, but it looks as though i am going to have to settle with doing a little moding of the current rig i have to get by for. . . .well, ever it seems.

anyway, i have a 1991 excab K1500 with the 4.3L TBI with blown rear main seal and leaks coolent and the nv3500. i do not know what trasnsfercase it has, i think its a np231? it of course has the huge 10 bolt rear and 8.5 IFS front. what i am planning is:

getting a recently rebuilt 350 that threw a rod at 6k (faulty rod, broke right at the base where it connects to the crank) and took the cam with it. im going to replace the rod, buy the LT4 cam with a 1.6 roller kit, installing poliece spec injectors and a performance intake (possibly even vortec heads) and headers (dont know what ones yet) also MSD ignition and decent plugs and wires. clutch will be centerforce.

getting performace chip for the computer to take care of differences in chips between the motors. i was told everything else in the electronic aspect will be the same, but will the wiring harness of my 4.3 work on the 5.7?

also want to get a NV4500, but they are $$$$$, none the less, will a nv4500 have a different crossmember or mount than my nv3500? would the flywheel be different? clutch? slave cylinder? with my xcase bolt up? what xcase will be needed?
and to finnish off the rear of the truck i will be getting a FF14 bolt milling 6 lug hubs and going discs and upgrading to 3/4 ton springs if i can find any. what year FF 14bolts will bolt to my rear springs if any?

so ya, ill keep ya all posted on this thing, just wanted to as a few questions form the pros really.

thanks,
Callen

the 350 you speak of, is it an lt1 or lt4? cause the cams arent interchangeable between a normal sb and an lt motor. lt motors drive the water pump off of the cam, among other differences.

the wiring is miles apart between the tbi and tpi. i guess u must have an lt motor if u are talking about police injectors. just realized that.

the 4500 and 3500 compare about as well as an s10 and a k1500. major size difference.

the 350 is out of a 91 pickup. and yes, i was told a LT4 cam will work in a tbi engine with roller rockers. i checked at the fullsizechevy.com and a few guys ares tunning them.

i never said anything about TPI, what i want to know is if the wiring harness of my 4.3 will work on the 5.7, which i cant see it not working because they use the same throttle body.

and explain why i need a LT motor to use the larger TB injectors?

as for the 3500 and the 4500 being a big difference, obniously, but will a corsmember from the 4500 bolt onto my halfton frame?

thanks,
Callen

the 350 is out of a 91 pickup. and yes, i was told a LT4 cam will work in a tbi engine with roller rockers. i checked at the fullsizechevy.com and a few guys ares tunning them.

i never said anything about TPI, what i want to know is if the wiring harness of my 4.3 will work on the 5.7, which i cant see it not working because they use the same throttle body.

and explain why i need a LT motor to use the larger TB injectors?

as for the 3500 and the 4500 being a big difference, obniously, but will a corsmember from the 4500 bolt onto my halfton frame?

thanks,
Callen
maybe the cam can be machined to work in a normal sb. havent heard of it, but that doesnt mean its not possible. that would be a cool setup.

i assumed it was an lt1 cause u were talking about lt4's and police parts, and i know that plenty of cop cruisers came with lt1's. those were the injectors i was thinking about. oops.

tbi harnesses are all the same from 4.3's to 7.4's. that should work fine. the different motors (4.3, 5.0, 5.7, 7.4) came with different injectors to match the size of the motor, but if u are changing them out u will be fine. the ecm will need some tweaking. im pretty sure u can just pop out the prom chip and put in one with the correct callibration. howell efi sells em.

i would imagine the 4500 crossmember would fit. they came stock in the gms from 94-96 iirc. but they are pretty rare. shit, there are probably already holes in the frame that will fit that setup already.

also, i dunno what the specs are on the lt4 cam, but tbi wont run with a very aggressive cam, it needs a good vacuum signal to run. i wouldnt go above 225* personally.

ive heard good things about the 2030 comp cam kit for the TBI, i may go that route.

some cop cars cam TBI, but the injectors pump a bit more juice than the stock TBI setups.

i have about $2500 to spend on all this, so the 4500 might be out of the question, but would still be cool as hell.

Callen