ADOR

(Factory 1999 camaro with factory (dead/MIA)v6/t5(have) going to v8. Have sbc but if the deal goes though I will pick up a lsx. )

I am working on the final decisions on the SBC before I turn on a wrench on a engine swap. I have considered keeping the v6 computer to make the gauges work, and just piggy back the aftermarket computer I have to the engine. If the pcm doesn't see enough feedback from the engine running will it make the gauges not work?

Injuneer

Tach and speedo are normally driven off the PCM. Fuel / Oil / Coolant temp / Volts are driven by sensors on the engine, not by the PCM.

The V6 PCM needs a pulse signal from the vehicle speed sensor (VSS) on the transmission. Then it sends the signal to the speedo, after adjusting for rear axle ratio and tire diameter.

The V6 PCM needs a signal from the cam position sensor or crank position sensor to know the engine RPM. If you are looking at a Gen 1 SBC, doesn't have those sensors. You might be able to wire from the coil directly to the tach, possibly with a filter.

ADOR

Thanks for the info. I knew the sensors on the engine pulled the info but wasn't sure if it went through the PCM or went directly to the gauges.

I have a older (1978 4bolt from a 3/4 ton van) two piece rear main 350. Pulled it out of my 55 Chevy 150 so I could test fitment in the 1999 this time home from work.

Since it will be a while before I can do all the body work the 55 needs I may just drop it into the 99. If not I will just drop it back into the 55. Right now the long block is stock as can be beside some headers that will most likely not fit the 99.

If I like the test fit I will be swapping to a Torker 2 intake (for height reasons, I want to keep the wipers) then go with 4v TBI and commander 950 pcm, also have a set of roller rockers and 040 casting heads that need to go on.

I have also considered a Lt1 (have a full 94 z28 parts car minus engine/trans/ecm/harness.) Have found one cheap, but haven't seen how complete it is yet. I wouldn't have to pull any thing on the SBC yet and I know it will clear the cowl. I have even looked for a complete but knocking LT1, would want to do the L99 3 inch stroke conversion for a 302.

I have also been looking at some of the LSX HD van and truck combos like the 4.8 and 4l80e together from the factory. But locally I haven't found a cheap oil pan and intake manifold that will fit properly. May just have to get a engine/trans/wiring/pcm and just save up for the rest.

Other combos I looked at were, L99 4.3 (baby LT1) backed by the T5. That would keep it where the T5 would live much longer.

I have a Th350 long tail shaft (shifter and Shift kit) and a stock 92 truck 700r4 in the shed. Been running rpm calculations with the stock tire size, these 3 trans and current 3.23 gears in the car and the 2.73 posi rear that is in the 94 to see what these combo would give me at 55 mph and 70 mph. That is normal HWY and Interstate speeds around here.

If I go with one of the auto trans I will most likely do the speed sensor mod to work the speedometer. Main thing on the project is I want

Been researching it into the ground. Unless a complete T56 falls into my lap for 600 like it did for my oldest boy.