I am towing this year with a yukon!

[shermantic]

It has 3:73 Gears and a 5.7 350 motor I am having trouble maintain speed on the hills what gears would help get me over the hump with out loosing too much speed and other stuff 4:11 or 4:56?

[Silvertwinkie]

This is not too uncommon. I have 4.10s and 6.0L and rather than beat up the engine, I opt to loose very slight MPH. I can, if I depress the gas, maintain my MPH. If you can't, maybe your engine is getting tired.

[ROBERT CROSS]

Originally Posted by shermantic

It has 3:73 Gears and a 5.7 350 motor I am having trouble maintain speed on the hills what gears would help get me over the hump with out loosing too much speed and other stuff 4:11 or 4:56?

Trans in 3 or OD?

I would use 3 on all but the--------------terrain.

[moosetags]

What model year is the Yukon, and which transmission is installed?

Brian

[slowmover]

If it's any help, we all used to, in the 1960's & '70's, used to lose speed in going up hills since that was only reasonable. Might get a running start at 'em, is all. In the mountains, constant wide-open-throttle was necessary to cross some passes. Note that WOT was maintained for ten, fifteen, twenty minutes. On others, constant 3000-plus rpm was the norm. This was on vehicles that had a better power-to-weight ratio than what you are driving, but with numerically-lower gears (3.23 or 3.21).

The advances in engine construction ensure that todays motors have better internal clearances and parts fit. They don't burn oil -- brand new -- at 500-miles/quart. Keep in mind that these "old" engines also lasted over 150,000-miles, untouched.

With todays sophisticated engine controls, they should last as long or longer. I wouldn't sweat having to work the engine hard; not one bit. They're made to take it, so use 'em. That's what the redline is for!

Maintaining speed is relative. If you can keep to the posted minimums, then you are fine. If you can't, then maybe it is worth changing the rear gear set. I wouldn't. Burning some extra fuel doesn't hurt anything. Maybe change the oil according to the severe service guidelines in the manual is what I'd do.

Going slowly up the hills, engine singing, is part of the fun, IMO. Too bad it ain't the old days where we flipped the air cleaner lid over just to listen to that giant set of secondaries on the QuadraJet!

[Aerowood]

Going over the Colorado passes I am more concerned with maintaining a reasonable RPM verses MPH. That's just part of it, Like turning the heater on to blow off excess heat when it's 95 degrees pulling the east bound lane of I 70 to the Eisenhower Tunnel.

[94Tri]

Just speaking from experience with Mustangs and 1 truck with 4:56 gears, 4:11's are probably the best compromise. A truck with 4:56 gears in Drive is really going to be singing at 55-60 MPH.

[somefun]

I have 3.73s and a 5.7L in a 1993 Blazer and a 74 27' Airstream and it pulls just fine! It does need wide open throttle over the top of Snoqualmie Pass to maintain 55mph (for a couple of minutes).

[shermantic]

I also have a 96 k1500 pickup with a 5.7 350ci / 4l60e trans with 3:73 Gears and it seems to have plenty of pep

The Yukon is a 95 with over 200K less miles then the 96 it has 5.7 350ci / 4l60e trans with 3:73 and its a real dog! (the 96 is the vortec and 95 is tbi is there that much differnce?)

[ROBERT CROSS]

Originally Posted by shermantic

I also have a 96 k1500 pickup with a 5.7 350ci / 4l60e trans with 3:73 Gears and it seems to have plenty of pep

The Yukon is a 95 with over 200K less miles then the 96 it has 5.7 350ci / 4l60e trans with 3:73 and its a real dog! (the 96 is the vortec and 95 is tbi is there that much differnce?)

Yep...The Vortec was a big improvement. Friends 96 Burb would blow my 95 away before the towing mods.

I liked the TBI's reliability though.