1988 1 ton suburban buildup

[xpndbl3]

1500 trouble free miles....well until last night. It seems the coolant level sensor in the radiator decided to jump ship. Luckily I had a spare on another radiator in the garage, but it left a 1/2" opening in the radiator until I got it home. Tossed the spare in there and refilled the coolant today. Looks like the metal clip that holds it in place had failed. Since it wasn't hooked with wiring I lost the old one somewhere at night on the road, just checked local parts stores, it's $50 to replace so good thing I had a spare. Hopefully this one doesn't fail in the future. The port is "D" shaped on the radiator so I can't use some heater hose to delete it with a plug, but that was the first thing on my mind to do. I trust a heater hose clamp a lot more than this thing wire. Might zip tie the sensor in place somehow so if it pops off at least I won't lose it entirely.

 

[dirtbomb]

Good build thread and Damn Sweet Ride! Hope to get engine problems worked out in my 88 V20. How's she doing?

 

[xpndbl3]

zip tied the sensor in place as well, no more issues with it. Also had the front wheels rebalanced because the geniuses at discount tire put those hammer on weights on the inside rim lip when I told them stick on weights only and the tie rods had rubbed them down to 1/4 of the size they started at and made them out of balance above 40mph. Still loving the power and driveability.

 

[ThrottleHappy]

So what kind of gas mileage are you getting out of her?

 

[xpndbl3]

Getting a combined 11.x mileage right now, it was 8 city and 11 highway, so I'm really happy since 90% of my driving is in the city. Only 3 mile trips across the interstate once a week tops.

 

[bftank]

wow i figured your mpg would have been higher than that. sweet ride still!

 

[ThrottleHappy]

For real, lower than I'm sure you hoped for. I get 12 out of my 88 v20 both hwy and city with the SM465. I've been thinking about a project like this for some time but with those numbers it makes more sense to just work with the 350 and not deal with the California bs involved in engine swap.

 

[sean257]

Awesome work man, nice suburban!

 

[xpndbl3]

SO picking up over 3mpg in the city isn't a "good enough" swap mileage wise? That's 30% better on fuel than it was before with a TON more power and no drivability issues like the TBI engine had all the time. Runs cooler, it's a lighter motor and did I mention 135 extra hp over that 350? No reason not to swap them in.

 

[Erik N]

I get 12 out of my 88 v20 both hwy and city with the SM465.

I get 11mpg in my '88 V20 whether driving 65 down the freeway with a tailwind, or crawling along the trail in 4low. Weird!

 

[bftank]

wasn't dissing on your swap just figured the mileage would have been better. i get that mileage with my tbi big block burb on 36's. not as much power though. i figured you would be getting closer to 15 from what i had heard with these engines.

glad you got it done, looks real clean!

 

[xpndbl3]

with this crap chicago gas, i'm doing better than most. Have read about guys getting in the 15 range on the highway with the swaps, but like I said I don't drive on the highway and it's all heavy traffic areas around here and stop and go non stop. Even picking up 3mpg is huge for me, I'm sure in less populated areas or roads the savings would be even larger. Buddies with 5.3L powered late model trucks are getting the same without the lift, 1 ton axles or 36" tires either, so I feel I'm doing better than them with no overdrive as well. It picked up nicely after I had another buddy wideband tune the truck and add some timing into the motor from the stock settings.

 

[bftank]

sounds like your lucky to get what your getting then. sometimes i forget what its like to be in the big city. here you can drive from one end of town to the other without stopping.

 

[xpndbl3]

Haha ya we have stoplights pretty much every half mile or so, I'm dying for the country lifestyle instead, maybe one of these years.

 

[xpndbl3]

well another little mini update here, picked up a trailer for my business and upon arriving at home I had no reverse, so it looks like it's time for a trans rebuild. Fluid is still pink and level is good as I'm always on maintenance for this truck, but guess it was finally time to give up the ghost. Now I'm running prices out for swapping in a 4L80E trans or rebuilding my th400. Can't find any info on how to find a NP241 out of a 90-91 suburban that had a 4L80E to run with the combo. Doesn't seem likely I'll find one online, but I'm looking.