vortec conversoin...

[hippi68]

so, i have a 68 fj40, that had an old 350 in it. my project, which was to put in an old sb 400 magically turned into a 89 vortec v8. don't ask how. ...

any how, i have gotten so far as installing the motor, mounts bell housing, ect. dropping power steering pump, smog pump, and ac pump. so, now the question. what's the best way to deal with the ecu. i have the wiring hanres from the truck i riped the motor out of. and the ecu. but there is a bunch of unnessicary stuff.
should i get a new hanress ?
i have heard there is a no ecu mod you can get for these. (its tbi)
also, i have a fule pressure question. do i absolutely need to put in a highpressure fule pump ? in the tank ? concidering i have two tanks that would suck. if i can bypass the need for the hight pressure fule pump would be nice.

any input or advice would be greatly apreciated.
thnx.

 

[terrx]

If you mean high-pressure like a TPI pump, 40 PSI or so, then no you don't need it. However you do need higher pressure than a carb. Spec is around 12-13. There are a few options for external pumps which is what I use. No need for internal, though some people run an internal in a surge tank fed from a second low pressure pump.

Just double-checking, are you sure it's a vortec motor? vortec's didn't come out until a few years later. If it is, more info is needed to know the best route on the ECM. A stock TBI ECM like the 1227747 won't work very well for vortec heads without being reprogrammed. Is it an 89 vintage L05 motor with vortec heads, or later vortec motor?

The stock wire harness can be made to work and there have been a few good DIY TBI threads in the last 6 months or so. If you haven't seen them take a look.

 

[cruiser7773]

x2 ON MORE INFO

Double check the Vortec status. If it is a vortec and you have the ecm, you can have it reflashed to work without all the factory electronic inputs. I had mine done by BTB Products, but I have seen others advertise here for cheeper. As far as the harness goes, there are lots of options there too. DIY with advice from the many posting here or, again, there are many companies out there building plug and play units. Up to you. Good luck. Oh, and as far as the fuel pump goes, I don't have two tanks but my '02 requires something on the order of 58psi min. to operate properly. I run a 100 psi in-line unit. You could tie the tanks together and have the return line go to one tank while you draw from the other.

 

[hippi68]

well now i am questioning what kind of motor i actually have. i have never actually looked at a vortec so i couldn't tell you the difference. any way to tell if it is a vortec motor and if it has vortec heads ? seems unlikely unless po put aftermarket heads on at some point ....

as for fuel pump, i figure if i have to do in tank i'll just put a fule transfer pump in second tank to primary.

thanks for the input, i'll try and look up previous threads about this stuff.

 

[cruiser7773]

Block serial no is the most foolproof way to ID the motor. You can google the number or hit the liberary for all-data. I am sure those closet GM freaks out there could offer up something more.

 

[terrx]

One way to tell is by the configuration of intake manifold bolts. Vortec heads have 8 bolts. Older non-vortec heads will have 12. Don't be disappointed if it's not vortec. If it's the L05 truck motor it will still make good power & torque below 4k rpms.

 

[hippi68]

kool, i'll look for that. probably the l05. i'll be ok with that. i'll get back to you all with the result when i have it. thanks again. cheers

 

[Medusa]

If '89 and TBI it is NOT a Vortec

 

[hippi68]

well, now i feel dumb. so, not vortec. not aftermarket vortec head either. that makes this easier i think. still have to figure out the wiring, but should be ok. still trying to figure out what i can drop out of the bundle. thanks ppl