Hey I just bought a 1994 GMC 2500 for work and it has a couple quirks that i need some help with. I am also looking for any specs. I tried the search button but really didn't come up with what I was looking for.

questions
#1... It has a 5.0 (305) with automatic. I wanted to know a little more about the motor. Compression ratio, head cc, roller cam,vortec heads, is this a OBDI or a OBDII , the SES light just came on today. I am very rusty when it comes to the older sbc stuff. I have been running a ls motor for 10 years..

#2... Gas gauges moves from full to empty while driving? The A/C panel small arrows for the temp. start blinking and are all lite up at the same time? Wierd buzzing noise under dash, not very loud but is annoying. Now brake lights don't work?

#3... what is the wheel lug pattern. Yes it has 6 lugs. Will the stock wheels fit from a 2001 silverado.

#4... What is being done about the clutch fan , would like to have a e-fan. How is the e-fans controlled?

#5... Engine has a slight miss.(I haven't checked the plugs yet) But if it came down to it can a 350 be dropped back into the 305's spot and still run the same computer with out modification?

#6... The front shocks are shot what is a good brand to swap it?

#7... The truck does not have power windows can I go to the wrecking yard and remove all the power window stuff from the same truck and install on mine? What about the wiring harness on my truck , will I have to modify at all.

I know alot of you are thinking damn dude you should of looked the truck over more and found one with the options you wanted before you bought it.
Yeah I know but in the current situation I am in I had to act fast cause my other truck is going to be repoed. I owe to much on it and the bills are stacking up so I had to let it go. So I had to buy a truck quick and this is all i found in my price range. So any help or advice on common problems or quirks with these trucks will be appreciated.

Thanks

 

#2 you need to change your sending unit. by either removing the bed or dropping the tank down. change fuel pump at the same time it will save you more headache down the road.

 

Thanks, is the unit like the NBS with the sending unit and fuel pump in one?

 

Yes it is obd I. I have never seen a 6 lug 2500 but if its a 6 lug chevy has used the same 6 lug for a long time so the 2001 wheels will fit. The E-fans are easy you just buy a fan wiring harness with a temp sensor on it

 

I have an 88 gmc with extras and a great running 350. its in the for sale section need to get rid of cheap.. let me know

 

Unless it was swapped in, That engine is not a vortec engine. That's a TBI engine. Believe the comp ratio is around 8.5:1. Block is possibly set up to be roller ready but is not a roller cam engine. not sure of the horsepower but I know the 350 TBI only had like 210 hp at flywheel.

 

Thanks for all the info. Keep it coming...

 

Update: Motor still has a miss. Pulled all spark plugs all of them are new and clean. I did a compression test on all cylinders all of them were between 135-145. The dist. cap is new. Wires seem to be ok. Anything else I should check for?

The SES light is still on. I was under the truck checking things out and saw that it has a knock sensor on the block right over the starter. It is not hooked up. There is a wire that is tied into the wires to the starter. It is a dark green color and is not hooked up to anything. The wire is heat damaged and has no end on it so I don't know were it goes. I am assuming it goes to the knock sensor?

Truck seems to run pretty good but has a strong rich smell from the exhaust. Maybe O2 sensor?

 

Also I put the 2001 wheels on the truck. The bolt pattern is the same and the wheels fit. Well kinda. The front wheels hit the upper a-arms for clearance I am going to grind the upper a- arms bout 1/2 inch or maybe use a wheel spacer. Also I can't use the center caps for the wheels on the front wheels cause the snout from the rotors sticks out to far.

 

#2 like the other guy said, replace the whole fuel pump/sinding unit while your at it, u will thank yourself later...and its easiest to just pull the bed bolts and prop it up as compared to dropping the tank...thats a real Pain in the ***
#5 yes a 350 will drop right in, but you may be looking at changing the computer which isnt hard or expensive at all(behind glove box)
#6 any local auto parts store will carry decent stock replacements
#7 as far as the power windows go, yes you can , but you will have to make sure ya grab everything or of course they wont work, ive dont that upgrade myself. just make sure its from and 88-98 same body style truck-chevy or gmc