Looking to get more wheel speed in my k20 it has 4:10 gears in it now and 38's and about a 400hp sbc and a 350turbo trans and 203 case. Thinking about swapping gears. But what would be the best gear ratio?
try high range if you want more wheel speed or bigger tires mabye? i run 38s and 4.10s and a 208 if I had 400hp id try a high range lol
Quote from: betterbeaters on January 23, 2014, 01:08:50 AM
try high range if you want more wheel speed or bigger tires mabye? i run 38s and 4.10s and a 208 if I had 400hp id try a high range lol
x2
what kind of 38s are you running?
wind it up and bump it into 2nd thats what i do. low range peak of the cam hit the next gear that with a 400+/-hp sbf c6 205
38 gumbo monster mudders.
And I do run high range.
the cheapest is the t case gear ratio from a 203 go to a 208 you'll drop 50 lbs and get a better low gear and you need to see what the truck is doing will it hold 2nd gear in hi range or is it dropping it and heating up your trans from the load.
400 hp and high range is barely enough to run 1 st gear with 38s.
Quote from: MR NASTY on January 23, 2014, 06:01:14 PM
400 hp and high range is barely enough to run 1 st gear with 38s.
its all about rotating mass boys n girls! get rid of the steel rims and go to a light aluminum rim billet aluminum hubs would also make a big diff. 400 hp is no where near enough power to run high lock! 600-700 hp is highlock range and it prob still wouldn't like drive with a 410 gear! everyone has there own ideas but my statements are tested not theories! highlock in the mud is very labor intensive on a transmission! I would say with 400 hp and 38s I would run a 538 gear at a minimum and keep it in low lock should run drive in light mud prob will not like it in the thick heavy slop!
mr nasty they bump there heads!!! hi range that's funny!!! how fast is any truck or car going down the road in second gear, with stock tires?
Yup that's for sure I run a light ass jeep 38 bloggers with a healthy 383 and 456 gears and it is a dog in high lock! Most people think a cam and intake get ya 400 hp but would be surprised if they actually dynoed there stuff and find out they are actually putting 250 to the wheels! Not saying this is the case here but I've seen it many other times. Definitely the less rotating mass the better
I have a .60 over 350 with flat top pistons. .510 lift 280 duration cam. 2.02 intake and 1.60 edelbrock aluminum heads high rise dual plane intake.
I'm picking up a 208 soon and getting rid of the 203 and then Probley going to 5:13 gears.
putting a 208 and 5.13s will slow the tires down.. you said you run hi range. it that 1st gear or 3rd? my 87 ran 1st in hi with a 4 spd stick worked its ass off and I had to dump the clutch at 5000 rpms to help it get going to 5500 rpm if I was lucky. swaped to a 350th with same tcase and gears had to run low and it was 1st and 2nd... my new motor is about 375-400hp and if I have time it will be dynoed like the last one lol but id guess ill use 3rd in low lock.
Quote from: marshall on January 24, 2014, 12:05:11 AM
Gutting the truck out will get you wheel speed. Remove all the glass, heat, wipers, carpet, sound deadener, lights, cut the doors up, gut the box, remove the exhaust, remove the bumpers...makes a huge difference.
Then put nitrous on it ;)
lmao
I agree with what others said above you SHOULDN'T be in HI you should be in low.
My jeep is 4000# 500-550hp 4:56's one tons, 4linked with 40" cut boggers and I run low range. By the way from the description you gave of your motor I don't believe it's 400hp but that's just my ==2cents
38" boggers 456s 3500 stall,true 400-475hp and I run 2nd gear low range
Quote from: marshall on January 24, 2014, 12:05:11 AM
Gutting the truck out will get you wheel speed. Remove all the glass, heat, wipers, carpet, sound deadener, lights, cut the doors up, gut the box, remove the exhaust, remove the bumpers...makes a huge difference.
Hell just sit on the frame and hold the bottle!!
Then put nitrous on it ;)
I would spend some time playing around with a gear calculator.
I also have a 3500 stall torque converter to.
I have close to same thing in a 76 long box a bit more motor talked to a guy in Indiana about making my 208 into a just high gear case and making it weight 45 pounds I have 39.5 boggers and 4.10 gears he said not to even do it unless I would have a high 5 to a mid 6 gear low range all the way
High range is very hard on the tran, get a new torque converter that works beat with you specs give Coan a call and tell them what you have and they will recommend a torque converter
Dump the 203 n go 208. There strong
I run th350/208 500hp with cut hawgs 44s, 4:88 gears SBC and can hit 3rd
Do not run hi lock, bad idea,
Go better gears and run through the gears
X 1,000 on what all the seasoned guys said ..
light wheels....is huge
And running light weight aluminum driveshafts is a great way to free up HP...and often overlooked buy many
proper stall for cam ...is like a no brainer
run high range if you want...it's just a trans...you can always rebuild it as often as you like
"IF" this is "not" a duel purpose street use truck....I would definately change for a more offroad oriented gear set
No2 is a great tool and can sometimes be just the trick to get you were you want to go !!! ;D
Here is a link to a great gear calculator. http://www.grimmjeeper.com/gears.html
I only wish I could own a truck that hit 2nd in high lock, damn I guess I do, somebody parked a dually in my yard