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73-87 Chevy _ GMC Trucks => Performance => Topic started by: Sierra4x4 on September 03, 2003, 12:08:00 pm

Title: Slow truck
Post by: Sierra4x4 on September 03, 2003, 12:08:00 pm: Current setup, Rebuilt 350, 4 Barrel Quad rebuilt (faily good condition), Dyno Max Headers, Edelbrock performer Intake, true Dual Flowmaster, no cats, 4 Spd Manual Tranny, Np 205, 10 and 12 Bolt Axles, 3.42 (or so) gears, 35 in tires. Which is gonna help out more with some takeoff/acceleration?
4.56 gears, New 'bigger' carb, MSD Ignition?
im thinking new carb since winter is comming up and gears after the snow is over... Any other ideas/comments?
Title: Re: Slow truck
Post by: 73K20 on September 03, 2003, 02:54:00 pm: Gears will make the most noticable difference.
1973 K20 - 350/350/205
Title: Re: Slow truck
Post by: Sierra4x4 on September 03, 2003, 04:50:00 pm: yeah, but i barely have enough cash to get one axle done, cant get through the winter without 4x4 hehe. how much of a difference would 4.56 make over a 3.42? And what is this 'case change' i keep hearing of?
Title: gears
Post by: cimfth on September 04, 2003, 10:26:00 am: Maybe you could find a good deal at a junk yard for and axle swap. I wouln't go with 4.56 if you care about fuel mileage. Maybe 4.10 that would help alot with acceleration and save a little more on fuel
Title: Re: Slow truck
Post by: Unixluv on September 04, 2003, 11:54:00 am: Gears will also reduce your top end. You haven't said what you are doing with your truck. Is this a street machine?

Edited by: Unixluv at: 9/4/03 10:54 am
Title: slow
Post by: Schinny2 on September 05, 2003, 06:30:00 am: I think a axle swap would be a cheaper swap. Find a old 3/4 ton with 4.10's in it. You can always change to 4.56's later. Then you would have the right carrier to change gears
Title: Re: slow
Post by: 73K20 on September 05, 2003, 08:00:00 am: The guys above where correct in saying that axle swaping would be cheaper. If i where you i would pick up 3/4 ton axles cheap and swap to 4.10's, they would just about be perfect for 35" tires. I don't think that 4.56's are necessary until you run into 38's or larger. If you're having acceleration trouble with a 4 spd tranny be glad that you don't have a slush box.
1973 K20 - 350/350/205
Title: Re: slow
Post by: Sierra4x4 on September 05, 2003, 10:00:00 am: Id love the axle swap but i doubt it would be cheaper, i can get the install kits for 80$ and the 4.56 for under 200$ an axle, installed for about 200$ an axle. Plus i wont know what condition the used axles are in, id have to buy new brakes, possibly wheel cylinders, calipers, new rims and mount my tires.... maybe ill look into it though. how can i tell if the axles have 4.10's without popping the cover or turning the wheels?
I did the math and 4.10 vs 4.56 was only about a 300 rpm difference on the highway. This is my hauler/daily driver/weekend warrior truck i plan on 37's when my 35's are out. my highway driveing is fine, but off the line at red lights it sucks my gas because it takes alot to get those tires going.
Edited by: Sierra4x4 at: 9/5/03 9:32 am
Title: slow
Post by: 77DuallyCowboy on September 16, 2003, 09:55:00 pm: ok, there are 3 EZ ways to tell.
1) on the glove box door is the RPO codes sticker, That will tell you what it came with from the factory.

2) on the axle carrier covers there is a tag that tells you what gears (I could be mistaking that with the limited slip tag though)

3) on the passenger side axle tube on the front side, for the REAR axle are some numbers stamped into the axle tube, copy them down and call a GM dealer, or look in a Chiltons Manual. (Hanes manuals SUCK)
On the passenger side, rear side of the front axle tube will be some more numbers stamped in, those will tell you the info for that axle. (i believe thats the location for the front axle codes) Chances are pretty good these numbers are worn away however, but its worth a shot.

Deffinatly 4.10's will get that neck snapping small block power back! Those 3.42's with 35's are basically making the final ratio more like around 2.80 or so! Gears are the only thing thats going get the low end power back, OR smaller tires.
Title: Re: slow
Post by: Sierra4x4 on September 19, 2003, 07:42:00 am: thanks for the info, couldnt find any #'s but i did pop the front cover to work on my axle shafts and counted it out to be a 3.33, yuck! Im going with some 4.56's, but it will wait till next year when i get it paid off and get something else to daily drive. That way i wont be so hard pressed for cash and wont have to worry about any projects being done BEFORE i have to be at work. That way i can get some more lift cutouts, gears and probably the cam ive been wanting for so long.