1993 search and rescue truck help

[hopelessredneck]

Well i thought i would talk to the experts you guys that know first hand i am a 4 year member of hope volunteer search and rescue group we have the jaws of life and many other gear on out truck it is a 1993 chevy 3500 crew cab dually with a 454 tbi and a 5 speed manual tranny the truck is up on the peak of its max weight limit and it responds to accidents in the mountians and when pulling the hills it bogs down and the 454 will eather be screaming in 3rd or bogged down in forth and it pulls out jet boat and inclosed equipment trailer my question is.....is what are you guys doing for more proformance in your 454tbi and what do u guys think of adding a two speed rear end or any other suggestion would be greatly appreaceated

[carsinsc]

What gears are in the rearend now? Maybe a lower gerar set would be the cure.

[70BLAZERX2]

I had a roadmaster wagon ..93 with a 350 I put on a 4bbl edelbrock intake with a marine 4bbl to TBI adapter..and had a ramjet 350 roller cam in it..I had to get an adjustible fuel regulator..And cranked it up 2 lbs over stock and it did super

headers and duals will help. and that should not have a converter on it being a heavy gvw..lose that thing..it will help also.

They also say the TBI spacers will help with mid rpm tourque

I alos have a set of 4.56 gears for the dana70HD rear axle...

I have a reman engine computer with a performance chip in it from a 90 454SS I sold. I do not know what it will do but if it will do something..I will let it go cheap.

Its the same chip thats on ebay that says 454ss "hot chip"

[Restrorob]

Originally Posted by carsinsc

Maybe a lower gerar set would be the cure.

I'll second this one, You'd probably be money saved drop'n a gear than trying to hop the engine up. You would likely see a little better fuel mileage running flat ground since the engine wouldn't be lug'n as bad trying to pull all that weight around.

[ChevLoRay]

I don't know what kind of budget you guys have. Gear Vendors makes an over/under-drive unit that doubles the number of gears you have. I think that the under-drive setup will give you more gears for the bottom end, but at the expense of your top end speed. That may allow you to keep the ratio you have, but give you more help at the low end of the speedometer.

[hopelessredneck]

Originally Posted by Restrorob

I'll second this one, You'd probably be money saved drop'n a gear than trying to hop the engine up. You would likely see a little better fuel mileage running flat ground since the engine wouldn't be lug'n as bad trying to pull all that weight around.

ya this truck dose a lot of hill climbing in the mountians in British Columbia canada

[carsinsc]

We have run 5.13 gears in our GMC 4500's. We have 19.5in tires, and Allison auto's , but the gears sure work nice. You will puck up mpg even at higher rpm's if the motor isn't lugging and it will drive nicer.

[70BLAZERX2]

I had to take the 4.56 out of the rollback here because i was running a 454/th400 and at 70 mph it was 4,200 rpm...with the 19.5 tires.

you could watch the gas ga. drop...

.I went to a 3.73 for the interstate runs..and not a cruise 80 mph at 3500 rpm..and then i am installing a 4 speed granny gear with a 3 speed "BROWNIE" trans behind that..I will have super low range...1 to 1 and a .85 overdrive..to drop the rpm even more..so i can cruise at 75 about 2,600 rpm...

Old 77 model 454 camper gets 14 mpg now..trying to get it in the 20 range..weights 9,000 lbs empty