INSTALLING A 93 TBI 350 AND 4L80E INTO 70 3/4 TON TRUCK NEED HELP!!

HELP PLEASE HAVE COMPLETE TBI ENGINE AND TRANSMISSION & WIRING HARNESS. THEY MAKE A FUEL PUMP KIT THAT INSTALLS IN TANK(TANKS INC.) HAVING TROUBLE WITH VSS ON TRANS TO MANUEL SPEEDOMETER AND WIRING. I HAVE WIRING HARNESS AND COMPUTER FOR THIS COMBO WHAT DO I NEED TO MAKE IT WORK?    

I'm tring to do about the same thing.  A 91 Surban 454 TBI & 4L80E in a 65 GMC.  Please help us!  

there are a bunch of articles on doing this swap in the dozen or so.. truck magazines.. and a bunch scattered around the performance group...

whats important..     if you can get your hands on the ignition key from the actual truck the engine came out of .. OHM the resistor pellet...   write that resistance value on the ECM with magic marker on some kind of tape...

 

there are 15 different values  it takes a long time to work your way through them if you don't know what the value was.. not impossible.. just time consuming..   probably 2 to 2 and a half  hours unless you hit the proper value  as each failure has a 4 minute time out before another value can be tried..  

why..   so it will start.  when you get it all hooked up..  

you will also both need a wiring diagram for the engine controls..  

there are only a few places you need to hook up power to...

both of you may also need to examine the ignition switches..    as the versions for point type ignition  disconnected the IGN 1 power to the coil when the key is in the cranking position.. and neither of the motors you have selected will likely have the R terminal on the starter to make up the difference...

i ran into this problem over at pontiac high performance..    since most gms used a similar dash mounted ignition switch.. you can update to the ones i posted over there.. in the next day or so.. i will try to get back to this post with part numbers for the dash mounted gm ignition switch and the proper replacement switch pigtail for the later switch..  the lock cylinders and bezels will fit in most applications..   so you keep your key..


there are only a few wires to hook up..  to power them up..

do both of you have wiring diagrams..  

u are discouraging me with this info as if it wasnt enough with the fuel pump,wiring issue and the transmission vss tailshaft to manuel speedometer at $500 plus it might be better to do a carb!! thanks!      

would i need the computer if i used this engine trans combo and just put a carb on this engine? besides the vss tailshaft change what kind of wiring harness would i need?  

well im getting discouraged!! but i have this complete combo with serpentine  belt system and all now im rethinking!  

this is a GREAT swap... do not be put off...

no swap is that easy.. no swap it cheep....  

knowledge of how it gets swapped before unbolting anything from the existing truck is needed...


if you wanted to run the 4L80-E   it does require a computer to shift it.. there are many different stand alone shift computers to do it..

there are carb type intake manifolds that will bolt to the heads...   you may still need an electric fuel pump as i don't know if the block has the mechanical pump mount or if the cam has the eccentric lobe for the fuel pump..


as for a mechanical speedo driver...  

as for the wiring harness hook up....   you will need a better wiring diagram than this..  this one is for a 94...

but i only see 3 places to supply power... for the ECM...



the red wire gets fused switched power..
the pink and black gets fused switched power.
the orange wire gets fused constant power..

this is a wiring diagram for a 91....   neither of these is good enough to wire your computer as all the grounds that are in the harness really are not shown properly...   i am taking that the harness is still completely attached to the motor...




is your ignition switch dash mounted or column mounted.. if dash mounted.. go for one from a 75 chevy van and the matching wiring harness available in most parts stores...  this might be just a swap to the replacement LS411 ignition switch for HEI vans .. verification that the IGN terminal has power in both run and cranking... so you don't loose power to the ignition coil.. as the later motor does not have the bypass wire from the starter ...  

i am taking this is the speedo driver you were talking about..


http://www.highperformancepontiac.com/tech/hppp_1007_electronic_speedometer_converter/index.html


you could always.. drive by GPS display...

i seem to recall seeing GPS speedometers that mount in the dashboard...  

since thats a big rig part... there might be a few floating around big rig junk yards...   might be able to pick one up for cheep....  

that link helps with the speedo and on the wiring harness i have everything from the back side of the fuse block even the exhaust pipes with the sensors all fuel lines from the fuel filter on the frame rail.no ignition key may be a problem and i found a kit for a in tank fuel pump for $195 and be able to use original style tank behind seat.think thats the way i want to go unless i use a 1972 sending unit wich has a return provision and an external pump (heard it was noisy) but may consider if i can get info on an external fuel pump that would support the tbi.u got me thinkin again obout how cool it woukd be to get this done!  

its totally easy to shorten the fuel pick up tube in the tank....  install the 25 psi TBI pump in the tank.. either drill or punch wires through the sending unit flange..  create some bulkhead connectors for it..  the originals are only rivets through plastic or fiber bushings..    nylon or phenolic plastic insulators of some kind..

punch a return hole in the flange also...   solder in a fitting.. use silver solder away from the tank...

this is high strength silver solder..  same stuff used to solder the fitting in currently...



creative people could take an existing fuel sending unit..  cut below the sending unit to mount the bracketed tube section to yours below the sending unit with compression fittings...


on one of the many forums... here i posted the proper pins to short together with a switch to make another 2 pins with a tiny light bulb attached to flash check engine codes...     make it really simple to figure out whats wrong...

i can also help you figure out what wires to hook to an ALDL connector to access live data with an OBD1 scan tool...  yep.. these have live data.. make it really easy to fix.. and to verify the engine is running correctly..  

one last things.. these TBI systems.. really require the oxygen sensor be properly installed and working..  the engine tunes its self with oxygen sensor readings..  can make a huge difference in fuel economy...  the whole fuel system is designed to be adjusted by what the oxygen sensors are doing..  fine tune it..

the return line can also be dumped directly into the filler neck tubing..  again.. making a hole ... this time using a tapered punch and bending it sideways.. sliding in a piece of tubing and soldering it in..  so you don't disrupt the fuel fill ...  

well the transplant is coming together! next week the engine and trans is going in then arizona tpi is going to make a harness for the engine and trans then working on the fuel tank ive decided on a fuel pump kit from tanks inc. gonna install it in a new fuel tank behind the seat in the original location. then the speedo converter and i should be ready to run it!keeping my fingers crossed!! can anyone decipher vin code i want to make sure i have a 4L80E trans. the vin from donor truck is 2GCFC29K8P1145934 I know its a 93 350 3/4 ton just not sure about trans as i dont have it in front of me yet to verify. thanks!!  

A pic of the pan might help.



 
When The Flag Drops,,,



The Bull Chit Stops,,,


P. Engineer, Engine Builder

THANKS TUFFNUFF THAT HELPS!