HEY MR.MIX....WHAT SETTING ON YOU HPP DID YOU USE WITH THE 3.90 GEAR.AND WHAT RPM'S ARE YOU RUNNING?HWY SPEEDS.I CANT MAKE UP MY MIND WHAT GEAR TO GO WITH.IVE GOT STOCK 3.42 RIGHT NOW.HERE IS THE PROBLEM,IM TRYING TO MIX EVERYDAY DRIVING IN WITH MAKING IT FAST.WHAT IS THE BEST GEAR IN YOUR OPINION.IVE BEEN LEANING TOWARDS 3.73...BUT SOME PEOPLE SAY THERE IS NOT ENOUGH CHANGE FROM THE 3.42???

 

there's really not a whole lot of difference at all from a 3.42 to a 3.73 . its slightly noticable at best. i am not saying you shouldn't do it , just don't expect a whole lot from the change in gears.

 

THATS WHAT IM AFRAID OF.BUT I DONT WANT TO HURT THE DRIVEABILITY BY PUTTING IN TO RADICAL OF A GEAR.I PLAN ON TAKING THIS TRUCK TO SHOWS...AND I WILL BE DRIVING IT.I ALSO HAVE TO DRIVE INTERSTATE TO AND FROM WORK EVERYDAY.SO ON A DAILY DRIVER,WHAT WOULD BE THE BEST WAY TO GO??
DO CERTAIN MODS CHANGE HOW EFFECTIVE A GEAR IS?IM RUNNING A WHIPPLE SUPER CHARGER WITH HEADERS AND EXHAUST ON THE 4.8 LITER.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by pbperformance:
<strong>there's really not a whole lot of difference at all from a 3.42 to a 3.73 . its slightly noticable at best. i am not saying you shouldn't do it , just don't expect a whole lot from the change in gears.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I run about 300 rpm's more at 70 mph than I did with 3.42's. I couldn't tell much of a difference from a dead stop, plus I did the converter at the same time. So I can't tell if I gained from the gears or the converter, but neither was much of a gain. I have been experimenting with LS1 edit using HPP as a base, and got total timing to 30 with out KR. Timing from a dead stop went from 14 to 29. That is the biggest difference I felt in this truck. But for gears, I would go 4.10 if I had it to do again. So I probably will before to long.

 

There is not much difference between the two. Do you race at the track,street,or just from a punch?That will make a difference which gear will be right for you.If you race more from a roll keep the gear that you have. You will want to keep your MPH. Do you have a stall? If not a stall will help you out. Especially with a super charger. As for my RPM's on the freeway I really haven't paid to much attention to them,I'll look next time and I'll let you know.

 

A 4:10 with a 29" tire will be around 650-700rpms higher at 70mph. So now if you are cruising at 70 with a 3.42, you are probably around 16-1700 maybe, with the 4.10 it would jump to 2300rpms or so. Still not bad but it is gonna suck more gas on the freeway. On my old car I have 4:10s with a detroit locker with a 26" tire and a 4 spd. 55 mph is 3000 rpm. NOw thats undriveable for a daily driver unless have plenty of time to get to work and a corporate gas card!