Its me again. Beau. I can never keep a username. Anyway. I've have gone as far as I'm going to go with my 454 in my 80 El Camino. Mid 13's in full street trim. I'm starting a new project with my daily driver El Camino. Its an 85 with a factory TBI 4.3/th200. I got my hands on a 5.7 from a 94 silverado that I just finished freshening up. I want to drop in the 5.7 and keep all the TBI intact. I have a few questions that need to be answered before I yank my motor. 1) Will i be able to re-use my current wiring harness and computer? 2)If I can re-use my current computer...can i have my chip reprogramed for a V8 or is it more complicated than that? 3)Do I use 4.3 or 5.7 sensors and if i have to use 5.7 sensors...should they have the same connections as the 4.3 sensors? 4)Will the factory electric fuel pump for the V6 be sufficient for the V8? 5)Do I use the starter from the 5.7 or the 4.3? Any other issues you can think of...please throw them out. I want this to be a weekend swap with few suprises if possible.
1) no. Your computer is for a 6 cylinder, not an 8. 2&3 are answered above. 4) I would say it should be sufficient if you aren't building the 350 up. If you add more beef you will need more volume. 5) the starter boss should be the same, and I assume the flywheel will be too. Provided the flywheel is the same you can reuse the starter Exhaust issues may arise as well. I just don't think the 8 cylinder ex manifold will fall right into the 4.3's spot. Also, the fan shroud will have to be changed. I'll think about this some more bud, and let you know if I come up with anything else. Good to have you back.
youre probably best off removing everything under the hood, and starting by putting just the motor in, and fitting everything around it. eric
I know the computer is for a 6. I've been to three different speed shops and i've gotten three different answers. One shop says that I can just drop the 350 in and change nothing in the computer and harness. All the computer does is adjust the air/fuel mixture to 14.7/1 and that it will retard and advance the timing on the v8 as it did the V6. Shop also claims that the sensors are not engine size specific. A quick cross reference in his computer claims that the 4.3 and 5.7 sensors are under the same part number. Claims even the throttle body is the same casting. I just have to change injectors. The other shop is telling me that I can re-use my computer but I have to have my chip "re-flashed" for the V8. I'm new to fuel injection so i'm taking his word. The last shop is telling me that I need the entire wiring harness and computer from a donor truck and I'll just have to manually lock up my converter with a toggle switch. The two shops say that I have to reuse my current computer because of the TC lockup. Its different than all other lockup converters. It uses a positive signal instead of ground. And the third want a toggle. As for the starter situation. The 350 is a one piece rear main and the 4.3 I have is the only year for the two piece seal 4.3. I was just wondering if it was the same tooth pattern. I THINK they changed the flywheel in 87(?) To be totally honest...i'm hoping the first shop i listed is right. I love easy swaps. But nothing is ever easy, so just my luck that info is totally false. This is my first time with fuel injection and it has be really intimidated. The only thing I DO know is that I can reuse ALL the accesories on my 4.3 for the 5.7, and i've aready upgraded the cooling system. In 83, El Camino's had a deisel option. With the deisel...you got a nice big 4 core radiator. Bolts right in with VERY little fabbing. Been having the 4 core for 4 months. Should keep the 350 pretty cool even in loisiana summer. And while i'm posting...maybe you can help me solve a small problem with my 454. When my daily driver went down for two weeks. I had to drive my 454 to work (45minute 1way). I would put new plugs in the day before work and by the time I made it home that night....they were burnt up. I had to change the plugs every few days. If I drive the car pretty hard, they dont go bad, but with normal driving they dont last. What would cause this? The motor isn't very radical. 049 heads light port work Edelbrock performer rpm cam " " " Intake Eddy 750 cfm carb 9.5:1 compression Super comp headers 1 7/8 primary any help greatly appreciated and thanx for the welcome back
The computer is for a 6 cylinder While it may compensate, it is still based on a 6 cylinder and efficiency with the 8 will be horrendous. Feul maps and timing curves are handled by the brain. Sure, I'll buy the sensors are all the same, and I know the accessories will bolt up. All the 4.3 is really is a modular engine of the 350 platform... They chopped off a couple cylinders . Mounts should be the same, and provided your new motor is post standard thread era you will be OK. I believe all 4.3s are cast and tapped with metric threads. The TB casting is the same? Hmmm, I assumed a larger CFM for the 350. I would not be surprised if the 305 were using the same casting, but the 350 surprises me... But there again, I swapped a 305 out of a pickup for a 350 with no external mods, including the TB, so maybe. With that being said, why new injectors? Are they really that much more flow? They really shouldn't be if they use the same casting. All the brain will do is maintain a greater duration for the injectors. You say it is a positive switched lock up? That sounds strange to me. Without having a diagram in front of me, I cannot be sure but GM is a huge proponent of ground switching with regaurds to 'puter controlls. They learned becuase of issues frying quad drivers... But oh, wait... Hmmm, yeah I'll buy that. There was an issue right around that time with lock up solenoids frying quad drivers and setting codes. It has been a long time since I have seen one, but I do recall replacing 1 or 2 puters and several lock ups about 10 years ago. What tranny in that beast? You say 200, is it a 200-4r? Also, is it the "square pan" or long pan? As far as flywheels, you are dealing with 2 differant engines. I had a girl who came in with a straight 6 Nova that was eating starters. Turns out, she ate a flywheel previously and the shop that put the flywheel in it put 1 in for a same year small block. It worked, but it was noisy as hell. a little looksy and we found the starter didn't engage the flywheel correctly, and the poor bastard was going into a bind. The 454, what do you mean by "burned up"? What color are they? Are they black and sooty, white and shiny, white and fluffy, or burned slap off? Also, what does the side and center electrode look like? What plugs are you using (make and part number), what is the gap, what is your base timing, and is the distributor curve worked? Is the cam advanced? When you crank the car does it turn really easily or does it hesitate? Finally, I assume you are using a non-EGR manifold right? I think the PRPM mannys come with and without. If not, explain the vaccum routing to me on the egr. I assume you are using a thermal vaccum switch off ported vaccum through a delay valve if EGR is set up.
So you would suggest the donor truck? Is the computer and harness a matching set or will a truck computer plug into the 4.3 wiring harness. I can probably find a pin layout of both computers but i wouldn't know how to read it so it would do very little for me. About the TB. I'm not looking for a performance engine. Just want the better drivability of the V8. I was told the 4.3 tb would act just like a 2 bbl carb and yield better low end torque. Sorry for all the dumb questions but this fuel injection has me terrified. I will be bugging you regularly until this is done so if i start getting annoying..let me know and i more than appreciate it. As for the 454. Its a real simple setup. No EGR. If it isn't nessesary...its not on the motor. Vacume is simple. From the tree on the manifold- to tranny, to distributor, to power brakes. Thats it. Timing was set by ear on test-and-tune night so i dont know. By burnt up i mean,,,the tips are BLACK. Not oil...just dark black and burnt up looking. If i let them go for a week...they will look like they are starting to melt. Running lean maybe? If I drive the hell out of it...i pull the plugs at the end of the week and they look great. All i use is AC Delco plugs gapped at .045
I give up. Too complicated. What does the computer control? What affects will ripping it out have? I can install mechanical guages but will my speedo work without the computer? Is my a/c system tied into the computer? Is my lighting tied in? Decided I dont know enough yet to tackle fuel injection.
