Carbed LT1
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Joined: Jan 2007
Posts: 6
Carbed LT1
Need to know:
What parts are needed as far as electrical for gauges and ignition.
What parts are needed for the actual change from EFI to Carb
What parts are needed for fuel as far as a pump and regulator
working on a 95 z28 6speed for a winter project and need to know what's involved. don't need to be talked out of it, just need the facts about changing over to a carbed setup. thanks
What parts are needed as far as electrical for gauges and ignition.
What parts are needed for the actual change from EFI to Carb
What parts are needed for fuel as far as a pump and regulator
working on a 95 z28 6speed for a winter project and need to know what's involved. don't need to be talked out of it, just need the facts about changing over to a carbed setup. thanks
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Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: Carbed LT1
Partial answer:
Gauges - Retain stock sensors for fuel level, coolant temp, oil pressure and charging system volts. None of thse are passed through the PCM. You will need to keep the PCM to drive the speedometer, or get an interface box like the one from Dakota Digital to allow the VSS on the T56 tailshaft to drive the speedo directly, and adjust for rear gears and tire diameter. The tach will need an interface. I know the 93 LT1 drives the tach directly off the coil, with a filter in the wire to the tach. Might be a way to retain the factory tach.
EFI to CARB - should be obvious - intake manifold, bored for distributor (there is a GMPP dual-plane LT1 carb manifold with provision for distributor, or you would have to convert a single plane Gen 1 SBC manifold, close coolant passages, relocate manifold-to-LT1 head bolts, and machine bolt head bearing surface to the correct angle, or redrill the manifold bolt holes in the heads), carb, distributor (pancake style minimizes the hacking under the cowl, retainage of wiper linkage), block-off plate for Optispark cavity (another GMPP part - not sure if they still make it). Depending on the height of the intake manifold and carb - a cowl hood for clearance.
FUEL - need a low pressure in-tank pump (6-10psi vs. 45psi). Might be a way to regulate the stock high pressure pump.
Gauges - Retain stock sensors for fuel level, coolant temp, oil pressure and charging system volts. None of thse are passed through the PCM. You will need to keep the PCM to drive the speedometer, or get an interface box like the one from Dakota Digital to allow the VSS on the T56 tailshaft to drive the speedo directly, and adjust for rear gears and tire diameter. The tach will need an interface. I know the 93 LT1 drives the tach directly off the coil, with a filter in the wire to the tach. Might be a way to retain the factory tach.
EFI to CARB - should be obvious - intake manifold, bored for distributor (there is a GMPP dual-plane LT1 carb manifold with provision for distributor, or you would have to convert a single plane Gen 1 SBC manifold, close coolant passages, relocate manifold-to-LT1 head bolts, and machine bolt head bearing surface to the correct angle, or redrill the manifold bolt holes in the heads), carb, distributor (pancake style minimizes the hacking under the cowl, retainage of wiper linkage), block-off plate for Optispark cavity (another GMPP part - not sure if they still make it). Depending on the height of the intake manifold and carb - a cowl hood for clearance.
FUEL - need a low pressure in-tank pump (6-10psi vs. 45psi). Might be a way to regulate the stock high pressure pump.
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