I have a 86 K20 with plow on front end.The truck has been owned by me for 1yr.In the last year I have put alot of time and money into this truck.It is used only for snowplowing, live NY State.Despite having a compression test done on it, garage cked 6 cylanders all meet acceptable readings.When I plow with it around 6hrs a storm if light ,truck out for8-10hrs.It stIll really has so little power going up fairly steep grades until it kicks into lower gear.It makes me wonder if the trucks engine is really going out. I sure do not want to continue to dump money into her if she is going down. What or how can I tell if the truck is worth keeping at this time.Briefly some upgrades, fuel filters,glow plugs ,relays,batteries,starter motor AND A BUNCH MORE.Ihave FORD powerstroke which I can get a plow on nxt yr.DAVE

If she starts up easily and doesn't smoke. If you conducted a fuel volume return check through the Injection pump. If you haven't noticed air in the return check. If filters have been changed out. If the fuel filler cap is ventng properly.
If the injectors have been serviced checked cleaned. I have seen more than several examples where those old and tired girls were brought back to spring chickens with newinjectors. I have seen old dogs run race the race tracks again. :)

Sounds like a normal for a 6.2L....... These are NOT very powerful engines at all.......

Sounds like a normal for a 6.2L....... These are NOT very powerful engines at all.......

x2.

What seemed to help mine the most was a "J" code spec reman IP(more fuel) and a non EGR single plane intake(better air flow).

Granted with the 700R4 mine had most of the power went into making the trans slip. :mad:

With the SM465 the truck isn't a lightning bolt but once moving(3.08 gears don't get you moving quickly) it speeds up quite well for a non-turbo diesel. Is it fast, oh god no, but it's better than it was when i bought it.

my 6.2 seems alot different than you guys. mine has fairly good acceleration and fairly good pulling power. sure its got a turbo but even before the turbo it worked great for me.

my 6.2 seems alot different than you guys. mine has fairly good acceleration and fairly good pulling power. sure its got a turbo but even before the turbo it worked great for me.

gear ratios help. 3.08s(in my case) are highway gears. 4.10s or 3.73s would help with acceleration.

gear ratios help. 3.08s(in my case) are highway gears. 4.10s or 3.73s would help with acceleration.

going downhill in a 6.2 helps a lot LMAO ya, mine always took off good with the low 1st 700r gear, but it was geared to high for the tires at hiway speed. when i get a set of 410's in it, it should be great

going downhill in a 6.2 helps a lot LMAO ya, mine always took off good with the low 1st 700r gear, but it was geared to high for the tires at hiway speed. when i get a set of 410's in it, it should be great

Mine's just the opposite. It doesn't get up and moving super quick but it's not too bad. Having no overdrive with the SM465 the 3.08s help there. I"ll be putting 33x12.5's on it for my next set of tires. Either that or 35's with ~4 inches of lift like your Jimmy has. That'll help bring the RPM down a tad on the highway. RIght now i'm sitting at ~2,000 RPM at 60 mph if i'm doing my math correctly.

don't goto big. get top gear around 1800ish at 60-65. goto big and it wall flat on its face and you won't be happy

my 6.2 seems alot different than you guys. mine has fairly good acceleration and fairly good pulling power. sure its got a turbo but even before the turbo it worked great for me.
x2, our 6.2 pulls strong, never had lots of trouble with it, its n/a but it makes our 6.5 look bad....:D

yea theres a handfull of them that start great run strong and pull hard. musta had some special sauce dumped on the pistons in the factory by some worker eating a big mac or something.