I have a 92RS with the 305TBI engine. I'm wanting to put in a 350 with a carb. Mainly because of the simplicity of the engine, plus the cost and the fact that I already have the engine. My question is what will I have to do to convert from the computer system to an old fashioned 350 without the computer, I plan on running a mildly warmed over 350 with a 650 holley and the stock T-5. My main concerns are the electronics. What all will I have to deal with. Such as the fuel system, the speedo(I've heard some things about it being controlled by the ECM. Any information would be highly appreciated. Thank You.......

 

I really think we need a Tech article on this, there is one but doesn't explain everything. I think if you just keep your harness in the car you will be OK just your torque converter won't lock.

 

Sence you have a T-5 you don't have to worry about the converter. I know the speedo in those cars are electronic but I don't know if they run through the computer. You will have to get another fuel pump (we put an external holley blue pump on ours), a non computer controlled distributer and carb and you will be in business. We did this same swap but in an 82 Z28 and I was suprised to find out that there are 2 differant wiring harness in the car 1 for the computer controlled stuff (distributer, throttle body and all related sensors) and 1 for the motor. I just unpluged the wiring harness from the computer and pulled the whole thing out along with the computer and voila it is just like any other normal pre computer controlled car. As far as the fuel pump goes I just droped the tank and pulled the pump off of the end of the fuel line then put a peice of rubber fuel line that was the same length as the pump in its place (so it would reach the bottom of the tank) and put it all back to gether then installed the Holley blue pump just like you would on any older car and have not had a single problem. Don't let the swap scare you it is realy easier than you think. I have always stayed away from cars with computer stuff and I thought this swap was going to be realy hard but after I got into it I found out that it was realy basic. Of course now that I have been reading this sight for a while I might even venture off into a fuel injected car someday.....lol.

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82 Z28 with 350.motor has .030 forged flat top pistions other wise stock bottom end, Summit 214/224 cam with 1.6 Harland Sharp roller rockers, stock 882 heads for now (will be getting a set of the 23 degree Trick Flows this summer), Performer RPM intake, Holley 750 Vacuum secondary, Th350 with 2200 converter, stock 3.23 geared rearend for now (getting 9" later on), Headman shorty headers, custom 2.5" into 3.5" Y pipe into M.A.C. offroad pipe and M.A.C. cat back system. So far car has only been to the track twice and is having sever traction problems but is running 60'-2.34 1/8 mile-9.2 @ 79 MPH.

 

The swap is easy. Just put on a carb and a non computer controlled distr and youre in business. The electronics (as stated) are two fold. Computer or Gauge. You can remove the computer wiring w/o hurting the gauges, which is what we want.

As far as the fuel pump, wouldnt the TBI work as long as you have a three port AFPR? Just knock down the pressure? The relay for the fuel pump still works (also independant of computer). If you do need a new pump, l put mine on the front fender in the engine compartment. No need, at least for me, to drop the tank. Of course, l was only having to contend w/ a 2 PSI fuel pump. With the 9+ PSI of the TBI system, why couldnt you just put a fuel pressure regulator w/ a retun line to drop the pressure to say 5 PSI? Just a thought.

Clayton

 

Hehe, didn't notice had a T5. Your convertor is your left foot. I don't know how long your tranny will last but the swap has been done.

 

Yeah, with a AFPR you can keep your stock pump which is suppose to be good upto 350HP in carb applications since the fuel pressure is so low. 4-6psi.

 

Hey guys thanks a lot. I've pretty much got this project underway. I'm going to install an adjustable regulator with a return line, as the stock pump is working fine at about 15psi. I'll cut her down to about 5 and everything should work great. Once again, thanks a bunch guys. I love this sight. Hopefully I can be of some help to you guys someday.

 

I just did the swap 3000 miles ago.Mine was a 89 Formula 305TBI Easy swap I've had no problems. TBI pump is rated 9-11psi regulate it down to 5 1/2 psi. The oil pressure/fule pump cut off switch threaded in above your oil filter into the block will needed to be used from your old moter or I think your oil pressure guage wont work.Also it is a good safety precaution. I'f you have any trouble or questions E-Mail me at
btsimmonds@seidata.com

 

The oil pressure sender drives the guage, the oil pressure switch acts as a relay for the fuel pump relay, if it doesn't sense and oil, your car aint gonna start.

 

i've got a stock 4 cyl pump on the 406 and it doesn't ever run out of fuel (450 hp). i was expecting it to this yr with the extra power, but it was okay at the race track and everything. i use a 3 port mallory regulator but i think you can use one from a holley blue pump.

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88 S10
Dropped 3/4
Dart equipped 406
12.20 @ 115.25 mph

 

You guys who have done this, what kind of emmission laws do you all have in your states? Has anybody done this in Oklahoma? I know we have no sniffer test but I don't know about visual. Just wondering if I can get away with it:-)...~Arnold

 

I have no sniffer/vet tests here either,when
I did my conversion my converter stayed put
but I will eventually replace it .I've got a
set of edelbrock headers that are going on just as soon as I can decide which cat-back
system to use. The swap is EASY,The wireing,
not much to it. Any Questions E-Mail me at:

btsimmonds@seidata.com
Thanks Bill

 

i have a 91 rs camaro and i just swapped my 305 to a good old 350, a 355 to be exact. I think i have all the buggs out now so if you run in to any hag ups just e-mail me.
ei_69@yahoo.com

 

You can also e-mail me with any questions you may have. I put in my 388 stroker three yrs ago but i didn't forget how FUN it was! I'm still using my intank pump, just using a Holley FPR to keep pressure at 7 psi.

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White 92 RS,388 cu.in.N/A
3.73 gears,auburn posi
Best 60 ft : 1.97
Best 1/4 : 12.679
Steve Spohn
Rear Suspension
Autometer guages
Extremely Loud Stereo !
Driven Daily
HOOKER LT's SOON!!! & 4 inch Exh.

 

Is there a post that list the parts individually to convert. Like, what harmonic dampner, what flywheel, starter, sensors, etc.

 

Also what about the 305 oilpan? Does an L31 Shortblock come with an oil pump?

 

I'm betraying my ECM ignorance here, but...

What about air conditioning? Doesn't the ECM control when the a/c clutch engages, etc.?

I have a freshly-built 350 in one corner of my garage, and a Camaro in the other. For me, the question about the peripheral systems is the last hurdle in getting the two together.

 

Ive already done this swap its easy. Just dont go sniping your wires and all that nonsense. Your spedometer will still work, i know mines a 91 same electronice system as yours. Just get a fuel preasure regulotor for your carb. throw the injectors to the side. Every guage will work except for tach, but you can rerun that easily. I know you have a t5, but my auto tran runs fine, just keep everything connected. Your service engine will light up, but you can just yank that out like i did. Im almost positive your t5 wont be long for this world after giving it that power, they can barely handle the 305 stock, thier pieces, and blow forks all the time.