[Guest]

Finally got around to converting to a carb setup on my 91 FWB. After installing an 87 L98 350 (Iroc 5.7) in my 91 which came with a 305 Chevy, the car started running like crap. Instead of messing with sensors or having the ecu recalibrated or any of that, I decided to do a carb conversion and hopefully pick up a few ponies while I'm at it.

Ran into a couple of problems but minor. I'm using a Holley contender intake, seems to have a cooling port on the passenger side front of the intake instead of passengers side rear that the stock TBI intake had, is this a prob? And more importantly, is this a cooling port? Could I hook up the cooling lines for the heater core to the water pump itself? It has a blocked off port that I could use.

Also having issues finding a proper throttle/kickdown/cruise bracket but I'll figure that one out. I'm eager to see how she goes with the carb setup. Besides the fresh motor (6k miles), I've installed a true dual exhaust with Magnaflow mufflers, high perf distributor and 3.73 gears. I bet I can outrun an LT1 Fleetwood or at least keep up with one. Cam and roller rockers coming soon! Thanks for any help.

 

[brougham]

Isn't that port the same one that the orange intake has on the front of it too?

 

[Guest]

Not in the same location. I just dont want to run a cooling line to the wrong port. :annoyed:

 

[Deep Sleep]

On the many chevy cars I had, The heater core hoses hoses ran off the back of the water pump ( the blocked off one you mentioned ) and the front of the intake manifold. ( the other blocked off one you mentioned )
To make it real easy, The two ports you have circled in you first pic are the feed (water pump) and return (intake port) for your heater core hoses.

 

[N0DIH]

The one on the back of the water pump is a suction line (water pump low side), can be used (commonly is) for heater core return. Some cars return to low pressure side of radiator (pass side top). In the intake crossover, that is for a temp sender or themal emissions control device. The one in the back of the intake is where the heater core GETS hot water from. It is a high pressure side port, picking up hot water off the block.

 

[DopeStar 156]

Ha, I'm interested in doing it the other way around.

 

[Guest]

Thanks for the help, I was fairly confident I could use either port but had to be sure. Thanks again guys. :cool2:

 

[the3rdalien]

When you switched to your carb., did you pull a fuse(s) for all those sensors, or just not connect the wiring that went to the TBI? My '91 brougham 5.7 has a hiccup I just can't seem to cure, and I want to get rid of the computer all together.

 

[Guest]

When you switched to your carb., did you pull a fuse(s) for all those sensors, or just not connect the wiring that went to the TBI? My '91 brougham 5.7 has a hiccup I just can't seem to cure, and I want to get rid of the computer all together.

I had that "hiccup" thing going on too and it got pretty bad. I'm almost done with the conversion but have not had the time as of yet. Its all on and ready to go, I just need to put the plug wires on, coolant back in and tighten a few things up. I just disconnected all the sensors and TBI for now. I know the service engine soon light will probably stay on and I'll figure out what to do about that after I fire her up and see how she runs.

Like you, I just didn't want to mess with the computer/sensors, so I opted for this. Hopefully it well net a few horsepower in the process. Parts you would need are as follows:

1. Intake for 87-93 Small block (I chose the Holley Street Dominator)

2. Carb (Edelbrock 650 w/electric choke)

3. Older style HEI distributor and stronger cam gear (I bought a Summit Street/strip HEI)

4. Fuel pressure regulator

5. New Throttle/Kickdown bracket plus spring return for the carb

Install was real easy (about 2 hours). Should have it running this weekend and will report on how it all turned out.

 

[the APEMAN]

It will be pretty interesting to see how the transmission behaves now since the computer controls it too.

 

[the3rdalien]

It will be pretty interesting to see how the transmission behaves now since the computer controls it too.

Do you have to throw a monkey wrench into it? Thanks for the advice, didn't think of that one either. So the trans gets thrown out too.
Your engine swap looks nice, Destroyer. Good luck. An engine check light is nothing but taking the bulb out, UNLESS, Apeman says that if you do that it won't complete the circuit needed for the trans to work properly,etc. I will check back to see how you made out.

 

[90Brougham350]

Nah, being a '91, it's still a 700-R4 / 4L60. Only thing controlling it is the TV cable. 4L60-E came about in '93.

Brian

 

[Guest]

Nah, being a '91, it's still a 700-R4 / 4L60. Only thing controlling it is the TV cable. 4L60-E came about in '93.

Brian

Exactly, its not computer controlled.

 

[the APEMAN]

My bad. One less thing to deal with.

 

[N0DIH]

BUT, TCC is an issue. Unless you have like 3.73's. Else, at slower speed cruise in OD the lack of TCC will overheat the trans and cause very early trans failures.

Prevent OD from engaging until >stall speed (55 mph or so?) to keep it cool. Install a LARGE trans cooler to help too. Most factory converters were around 1400 rpm stall. Give or take. More power or heavier car will make stall rise.

4L60E came in 1994.

 

[Guest]

BUT, TCC is an issue. Unless you have like 3.73's. Else, at slower speed cruise in OD the lack of TCC will overheat the trans and cause very early trans failures.

Prevent OD from engaging until >stall speed (55 mph or so?) to keep it cool. Install a LARGE trans cooler to help too. Most factory converters were around 1400 rpm stall. Give or take. More power or heavier car will make stall rise.

4L60E came in 1994.

I never thought of that but luckily I do have 3.73's. A trans cooler is not a bad idea though.

 

[the3rdalien]

Exactly, its not computer controlled.

The Haynes manual ( not very good in IMO) I have says the computer controlls the TCC in the trans.

 

[the3rdalien]

I had that "hiccup" thing going on too and it got pretty bad. I'm almost done with the conversion but have not had the time as of yet. Its all on and ready to go, I just need to put the plug wires on, coolant back in and tighten a few things up. I just disconnected all the sensors and TBI for now. I know the service engine soon light will probably stay on and I'll figure out what to do about that after I fire her up and see how she runs.

Like you, I just didn't want to mess with the computer/sensors, so I opted for this. Hopefully it well net a few horsepower in the process. Parts you would need are as follows:

1. Intake for 87-93 Small block (I chose the Holley Street Dominator)

2. Carb (Edelbrock 650 w/electric choke)

3. Older style HEI distributor and stronger cam gear (I bought a Summit Street/strip HEI)

4. Fuel pressure regulator

5. New Throttle/Kickdown bracket plus spring return for the carb

Install was real easy (about 2 hours). Should have it running this weekend and will report on how it all turned out.

Well?...How did it turn out? I hope it was good.

 

[Guest]

Well?...How did it turn out? I hope it was good.

Turned out great!. Started right up and after adjusting the distributor it ran awesome. I was really surprised that it sounded different out the exhaust. Quieter than it was with the TBI but nicer. Feels like its got more power from any rpm. After I drove it for about 30 miles I noticed a small fuel leak from the brass connectors at the fuel pressure regulator so I need to fix that and once again I'm not driving it. I also need a new air cleaner assembly. Small things though, I'm just happy it runs so damn good and I no longer have to worry about sensors and computers. Check engine light stays on constantly but I noticed no other side effect from the swap.

 

[N0DIH]

Lightbulbs can come out easily....