1988 suburban

[marinus69]

Hi all
I have a 1988 Chevy suburban that I use for pulling my camper. This is the second suburban of the same year that I have owned. The first was a 3/4 ton but unfortunately the frame was so bad that I had to replace it with a 1/2 ton. (same exact color and interior). Although I love the truck, it is way underpowered compared to the 3/4 ton.
Does anyone have some advice on how to up the power on this baby so I can pull my camper up a hill without feeling like it's going to die?
(rear end gears, transmission?)

Thanks
Rene

 

[1987 GMC Jimmy]

Is this just a regular TBI 350 with a 700R4? I would go through the RPO sticker in your glovebox and decode it to see if you can find what rear gears they gave you so we can go from there. I would go through the basics first like making sure the ignition (cap, rotor, plugs; wires if they're corroded or damaged) is tuned up. I'd get a timing light and make sure your base timing is good. If it's too retarded, it'll act like a slug. You want 6-8* BTDC but retard it a little if it pings. You'll know if it does. All you have to do is unplug the single wire, weatherpack connector on the passenger side firewall, loosen the distributor bolt and turn to adjust. Reverse to finish it off. Cite your catalyst sticker and check for vacuum leaks, and I'd pay special attention to the MAP sensor to verify that it's not a significant elevation change that's causing your issue. Repair them with new line if needed. Finally, I'd check your fuel pressure to make sure you're getting enough fuel from the pump, especially since it's struggling uphill. You want about 13-15 pounds, I'd say.

 

[yevgenievich]

Likely because of the gearing. But the 700r4 might not be too happy about the trailer. Make sure it has a trans cooler. Unless the 3/4 one had a big block, engines are almost the same, small differences in the cam.

 

[glockholiday]

My 88' has 3.54 gears. While I don't tow, I did install 33" tires and it's way too tall geared. My next big purchase is going to be a set of 4.56 gears and lockers.

My Suburban shows it came with 29" tires stock so this chart puts me way out of the curve for ideal gear ratio. http://4lo.com/calc/geartable.php