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Unfortunately there is no simple nor cheap way out. My basic recommendation for anyone with limited means in tools, work area, finances is to never buy anything newer than 1986, that's the last year of carburetors and HEI. When EFI, which is pretty reliable until it either fails with old age or somebody as in your case carves it up the road to restoration or replacement is complex and expensive.

For a carb conversion:
The heads on that engine do not accept older intakes. GM changed the angle of the intake bolts along side of the plenum. You need to either egg those holes in older versions or buy something like the Professioonal Products or ProComp intakes which come with adapters to fit the 86 and older heads or the 87 through 95 heads by flipping the adapter over.

For the fuel supply you need a bypassing type regulator, necessary fittings to fit the 3/8ths pressure lines from tank and to carb, and fittings for the 5/16th return line. Plus an inline fuel pressure gauge so you can see to trim the pump pressure from 12 to 15 psi down to a carb friendly 4 to 5 psi. The bypass regulator is to keep fuel flowing through the pump to cool its motor otherwise it will burn out in short order. You can find inexpensive bypass regulators that work well off EBay for a lot less cash than the name brands, stay away from anything using AN fittings as this stuff is unnecessarily expensive. There is a relay either on the firewall or fender that operates the pump, pry the connector apart and connect a hot wire to the gray wire leaving the relay, this will bring up the pump and fuel gauge. Wiring through the oil pressure switch will not work for safety as the computer does the count down, you will have to pick up an analog version at the parts store.

For a distributor a standard HEI can be used, you will need to supply it with a switched 12 volts.

You will find the little stuff like a carb throttle return spring, plumbing the heater and bypass will be a pain in the butt, as will be all the little details. You can't just go cutting wires as the computer stuff and the housekeeping stuff are in those bundles, so teasing the wiring mess out to clean things up takes good wire manual and patience.

Bogie
 

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Two barrel Holley to TBI intake.


https://www.ebay.com/i/282088497243...0%26rvr_ts%3D9946a8021690ad4ff1a27786ffdfdd02


You'll need a bypassing regulator to cut the TBI pump 15 psi down to a carb friendly 5 psi, a gauge and fittings to read that pressure. EBay is a good place for such a regulator at an affordable price. An HEI distributor which like the fuel pump you'll have to wire up.

The pressure line to the TBI is basically 3/8ths, the return is 5/16ths. They are actually metric but those US sizes will connect, you'll probably have to cobble some adapters.

The pump uses a gray wire out of the relay that is either on the firewall or the drivers inner fender, just pull the connector and plug into the gray wire that will run the pump and fuel gauge.

I'd just run a new hot wire for the HEI. If you wish put in a dual pole, dual throw switch on the panel to supply 12 volts to the pump and HEI from a fresh fused source. A safety switch for pump is a good idea, There is a GM 3 contact switch that screws into an oil pressure port. It is a closed and open switch, when the starter is engaged it provides fuel pump and cranking. Once the engine fires and you stop cranking it opens that circuit and closes another with oil pressure to keep power on the pump. In the event lost or interrupted oil pressure the power to the pump is shut off.


Bogie
 
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