suspension/gearing/slicks

[85SBC400]

ok guys, i've got an 85 chevy fullsize shortbed that i'm wanting to set-up to run points next year at our local 1/8th mile track. it has a mild small block 406/stock th350/stock stall/stock gears and suspension.

i want to start working on this thing little at a time from now till the beginning of next season so that i'm ready to go.

what are some things i need to be looking at as far as suspension/gearing/slicks for the truck? stock suspension? what would be a good gearing for the truck for 1/8th mile with some street driving around town, and whats a good size slick to start out with? if i have to tub it i will but i'd like to stick to a size that will fit in the stock space.

would 28-10.5's be fine or should i go with a wider slick like a 28-12.5?

i know there will be testing to do with whatever i choose but i'd like to get somewhat close to where i need to be from the start.

thanks guys.

[djracer]

I would run 3.73's or 4.10's and maybe a 29.5 or 30 inch tall tire. A taller tire has a larger contact patch without tubs. and of course a good posi and c clip elimintors would me a good idea. I also would get a small stall convertor. Ptc makes good stuff and can help pickout what you need. I can get you a number if you want.

[85SBC400]

sure thing. i'm going to start on this thing in the next couple of weeks, getting parts together anyways. so like a 30x10.5 tire and 15x10 wheel size? and like a 3k stall?

[Rodms]

DJ I started with 456 gears and almost made the pases in 2nd bearly got in 3rd 50' from the finish line,I would start at 488 but I don't know your weight either,I'm about 3500lb and run 10.5/30/15 on 10'' 5'' backspace rims and if you put any wider you got to cut.I also run 513 gears with a 5000 stall 12 bolt truck rearend ,this year axle will be cut 6'' and lowered 4r 3f my cam grind is 300b-6 Comp

Take your tranny out and full manual valve body first and converter

[Rodms]

85sb400 the key is to get that sucker in 3rd as fast as you can with the rpm range a t the right peak!!!!

[Super73]

Is this a max effort 1/8 deal?

If so, I'm with Rodms on this. I'd try to run a 30" 10.5 tire with a deep gear.. The taller tire is going to help hook just as much if not more than the width. Then you can also run a 10.5" class if you want.

Any idea on what RPM your going to spin to?

A 30" tire with a 5.13 assuming 15% converter slip will let you go 96mph at 6,500 rpm in third gear. This does not factor in tire growth. So it might be closer to 98-100mph with a bias ply slick.

I'd also put it on a dyno before you pick stall speed. You want a stall that is going to put you at peak TQ give or take 200-300 rpm. Then you also know what you can realistically spin it too.

As far as suspension, Caltracs and an adjustable shock for the rear should get you by. For the front, the best thing to do is get a weight and figure out what Moroso spring will work in it again running an adjustable shock.

[Rodms]

You need to know your cam range mine is 4200 -7200 and for me it is 1/8 run what you brung,but 85400 I'm on the track only,If you want to run points races you better have enough hid to cover a bad light without breaking out,and it always helps to play with their head!

[hotrod 80]

4.88 is awlful steep for a street truck with a 1 to 1 3rd gear . Id say 3.73 or 4.10 . Also true ten five racing is big around here , and there take offs are around $125 to $150 a set , and they are 28" to 29.5" tall with 6 passes on them . Just something to think about .

[Rodms]

85sb400 like I said do you want to go to the hamburgerstand or race points?

[85SBC400]

hey Rodms, can i get some shots of that tire set-up on your truck? the 30-10.5-15 is what your run right? on a 10" wheel?

[Rodms]

10-4 tomorrow

[djracer]

I was under the impression he still wanted to be able to drive it on the street some. If you go with anything over a 4.10 you wouldn't be able to drive it on the street. It also would be easier to get it to hook with a 4.10.

[Rodms]

Your right DJ if he wants to ride on the road he needs to keep it mellow,but he said he wants to run some points races,I hope he ventures out to my tracks ,I gonna count the cars!! HA HA

[Rodms]

Originally Posted by djracer

I was under the impression he still wanted to be able to drive it on the street some. If you go with anything over a 4.10 you wouldn't be able to drive it on the street. It also would be easier to get it to hook with a 4.10.

he could do 456 but if he locks the rear its not gonna be street very much besides down the backroads

[SpdBoss]

just drag it lol

[85SBC400]

hmm, my post earlier didn't post......anyways, here we go lol.

ok i know the bracket scene guys cause i've been racing bracket style here at this track on fun&grudge night for the past 3 years. sold the mustang drag car cause i wanted to start drag'n the truck. i think its just cooler to have a fast truck whoop'n up on some cars lol. what i ment by streetable is being able to drive in a cruise night or take it out to the hang out spots on the streets on a sat. night or something. nothing out of town and nothing daily driven.

yes its going to be 1/8th mile only, the track is only 5 miles from my house where'as the closest 1/4 mile track is about 2.5 hours away.

i just know nothing about setting up a truck for drag, its always been foxbody mustangs i've drag'd.

lol, yeah yeah.....lol i know, i want my cake and want to eat it too.


i've always wanted a mean street vehicle but i guess since i've decided to dive off into the points races and season's runnings i have to make up my mind what i really want huh lol.

ok, ok, its drag strip only then.

but going the way your talking Rodms would it be out of the question to drive it to the drag strip? we are talking about 5 miles one way and an average speed of about 45mph? i dont have a trailer YET.on my list of things to do. but i dont want to not be able to start the season next year just because i dont have a trailer.....i mean i can always borrow from a friend but i hate doing that. i'd rather just be able to drive it there till i can get my hands on a trailer. and for now, i'd rather drop that 1200+ that i would on a trailer into the truck.

or am i not thinking right?

i always drove my mustang to the drag strip, locked, 4.30 gears and a C4.

[Super73]

Assuming 15% slip, 45mph in third would be 3,000 rpms with a 5.13 and a 30" tall tire.

[hotrod 80]

I guess im missing something here . If your just bracket racing , loosen the converter alittle, add a posi, change to slicks at the track and race . Index racing would require only upgrading to meet the slowest class or class choosen . And any heads up stuff would require a major rework . When Bracket racing don't you dial in your time and attempt to run that time ? I would think you could run the points in a 17 sec ride , as the points stay with the driver not the car .

[Rodms]

I think he wants to run better than 11.00

[djracer]

Originally Posted by Rodms

I think he wants to run better than 11.00

that should be pretty easy in the eighth.

My old 89 extended cab went 9.20 on radials with a 3.42 gear.

[85SBC400]

yeah that is true about the bracket style racing but i want to run some decent times at the same time.....

looking to get into the 7's hopefully with this truck for this next season and build a big block for the season after that and go for 6's.

i kinda have a long term plan here lol.

thanks for all the input guys, your being a ton of help for sure.

Super73 - that wouldn't be too bad to drive it to the track then huh? 5 miles one way?

[Rodms]

Well iI can tell you your not going to see 7 with 410 and 373 and be lucky with 456

[Rodms]

He you go buddy see if this helps any some are from under so look for the fenderwell bolts its all stock suspension

[Couch]

just my opinion but 4.10s isnt low enough for the 8th. i daily drive with 4.10s and a 28'' tire through a th350.if this is just a sometimer for the weekend to take to the track and mob around town here and there i'd say stall and gear the helloutta it.but again thats all IMO

[Rodms]

If I were going to keep it on the street I guess I would do 456 and run it in 1st and 2nd at the track and you should be in the low 9 or high 8 If I'm thinking right,what rear do you have 10?And couch before I started putting this truck together I ran what they called 411 gear with a 1982 corvette engine and it was my work truck,I hauled ceramic tile and marble and tools It got about 13 or14 mpg OOPS my bad thats the dually F**d 410s is right