Question for you DRAG RACING guys! or Pro Street???

[smoknbarrels]

I need experienced help here.

I am making my truck into a pro street SWB and putting a 4 link in it.. I am running 29x18.5 M/T sportsman pros... the question is: what kind of speed should I try attain when I shift out of first at 6000 rpm??
I am trying to pick a rear end ratio but I don't know which yet..
should I be going 44 mph? or 50 mph?? less??

I also need to buy my tranny right away, and was thinking of getting the TKO-600
1st 2.87
2nd 1.89
3rd 1.28
4th 1.00
5th 0.64

but the gears are not the best. because if I make 1st fairly tall (by changing my rear ratio), then I will be going way too low of rpm on the hiway in 5th when cruising.
Any reccomendations (besides going automatic) know of a better tranny for me that will hold 600hp and run quiet?

I know there are lots of questions here, I hope someone can give me some insight.

[cooters]

you need to know what speed you want to acomplish at road speed, or the rpm you need to be at on the end of the quarter mile if you race it. Trannys are dike a diff, a 4;11 rearend will make your truck spin less than a 308 will if you have good power, so higher gear in first is better

[smoknbarrels]

see, here is what happens if I work it the way you illistrated, the first gear only goes up to 41 mph.. I think that will be too slow, i think it will be like a granny?... sure the 5th gear is great and at 65mph I am only cruising at 2141 rpm's (would be perfect)
and I estimate that my truck will never go over 117 mph in the quarter mile anyway..(if it did I would keep it in 4th till she blows! haha)

perhaps this tranny is no good for me? but what speed for a first gear or ratio would be ideal? without trial and error..

[Robznob11]

your motor selection is what will dictate your rear end speed, you see if you want to go fast a cruse at good rpms you have a delema.. if go with a low hp motor or one that makes its hp on the big end of the rpm band you will need low gears and hi stall to get it out of the hole to make a good quarter run, or it will be a dog off the line, this means you would have a hard time crusing with this engine becuas of gears and stall being so high and deep, (gas guzzler that won't live long) now if you can build and engine with massive tq and good hp your engine will over come the need for deep gears and will actually performe better with higher gears and taller tires, also less stall cause the engine ulilizes the whole rpm band, the secrete is to build your engine to suite your needs, why build a hi rpm motor when you plan on staying in the mid rpm band mostly. a gear vendors unit can overcome some of your issues

[smoknbarrels]

well my engine is going to be a 454 pushing at least 500 hp (flywheel) I will be using a 292H cam that will be good from 2500rpm-6500rpm.
I will not be using a stall at all, since I am going standard.
every once and a while I will take it out on the hiway... but I still want it lumpy and hi-horse power...

[cooters]

41 mph in first gear (65 kmh) is actually very fast for first gear, i would think 30mph (50 kmh) is plenty fast for 1st

[57sailplane]

question have you bought a 4 link yet.. if not i would hold off and just run the rear trailing arms with coil overs.. thats the way im going and djracer owns the world famous 67 short box that truck runs real fast... heres an old picture of his truck before he owned it, i think hes going even faster...

sorry about the picture, i got the wrong one from my photos. i was messing with grill styles..

[smoknbarrels]

Yea, I wanted to keep the traling arms on.. but now my tires are too wide and not sure how i will make them fit with trailing arms? I haven't bought the 4-link yet, as I don't know a whole ton about them yet (I'd have to do a little more research).
Possibly I could bend the trailing arms in somehow?
my rims are 14" wide and 3.5 offset so they are really deep, I'd have to move them in a lot. has anyone done this with good success?

[57sailplane]

oh ya and to answer your qestion. man there is a lot of things that determine final drive ratio as far as the quarter mile. first how much does your truck way. secound what kind of hp and torque is your motor going to produce.. if you are planning on running standard weight probably around 3600 lbs and have enough torque and hp. the lower gears would be better. cause you will be going faster and quicker. see it works like this if your hp curve maxes out at say 6000, and you don't have enough hp and torque to be runing at the end of the quarter at 6000 gand in forth then you may want steeper gears.. you may not even want to use all four gears. it really depends on your set up.. i would say find out what your motor is pushing or get at least a good calculated guess and go from there.. there are a lot of people on here with the desk top dyno.. thats not a garentee but a good place to start..

[corn]

A 4 link is a little tricky to get dialed in if you havent done them a few times. If you are going to change to an aftermarket suspension, Id go with ladder bars...

[cooters]

you gotter cornfed, ladders all the way. You just have to be a little more careful turning in and out of parking lots as the links dont like it when the diff articulates

[smoknbarrels]

What do you guys think about the first gear speed thing? think 41 mph @ 6000rpm for my '67 truck is good or bad?

[RACINJASON22]

Not real up on years of trucks and drag racing. But I have been into racing and gearing (circle track) years. From what I'm thinking 41 mph @ 6000rpm is very respectable since you will be running a standard tranny (stated) there will be more room for improvision on your part. Just my thoughts. RJ22

[bigjimzlll]

On my truck, I shift out of 1st gear in 1.3 seconds. It does zero to 60 in 2.4 seconds...so I would guess its about 30-40- mph in first. Oh yea thats at 7500 rpm

[djracer]

First off who butchered the grill in the pic of my truck. YUCK!



Personally I would definatly keep the trailing arms without a doubt! second I think 41 is great for first gear. A granny gear would be more like 10 to 15mph. in first. Make sure to put a small dome in that 454 compession will help it allot!

Kevin

[Robznob11]

ok ill try one more time never heard of any one running a hot rod with out at least a 2500 stall, i have desk top dyno and desktop drag if you could give me most of the specs of the engine i could build it and see its hp and tq curve, then i could put it into desk top drag and i would need your pick up weight, wheel base tire size, and i could find the optimum rear end ratio for you. i could swap several diff trans for you to see witch is best for the quarter. my 496 shoud be about 650 hp 650 tq starting at 450 tq around 2000 rpm it says my best quarter set up is a th400 with 373 gears...

[1968SWBBigBlock]

Change your back wheels and those tires will fit your trailing arm suspension.
You need a Neg offset wheel.

[prostreet1967]

Personally I Would Go With The Four Link Setup More Adjustability And Alot Lighter Than Stock Trailing Arms For The 6000 In First Sounds Good. Try A 5.18 Gear I Think Is The One I Just Ordered For My Uncles 55 With A Big Block Turbo 400 And 33x21.5x15 He Loves The Launch

[dog68chevy]

here my 2cent I go try 4.11 or 4.56 w/ladder bars and take off the m/t and
put hooiers on. you have to fine your happy medium between strip and street
fast time or half descent mpg .i have 68 c10 sbc,400 and 3.50 w29 hooiers
and from my home to carisle i use about a 1/4 tank of fuel.
Im going to make some changes i want it to run 11.60s so idont have to put
a cage in the comb im thinking of is a 454 30 over 400 and 4.56 and shifting
at 6000 to 6500 i should be in the ballpark there.We had a68 camaro
same combo ran 10.50 weight diff.
just so info.Rob

[hatchetman]

My truck hasnt seen a highway in years!Ridiculous gears and a small block!Anyway that solved my problem.

[Robznob11]

the low down desk top drag says ill gain 1.5 tenths by going from 3.73 to 4.10 and anothet .5 going to a 4.56 after that i start loosing , 3.07 is a quarter of a second slower than 3.73 this all assuming a 3600 lb short bed with 15 wide 30in tall mild race tires an th400 behind a 496 stroker pushing 630 hp and 640 lbs now the engine has 450lbs at 2000rpm and shifts at max witch is 6000rpm max tq is at 5500 max hp noses over at 6000 rpm. beings this is a 9.5.1 comp street motor with a mild roller cam 3.73 will give me alot more drivabality on the street and if i need to make up that extra 1/4 of a second well thats what that bottle is for, I love going fast but i also like to enjoy the looks on peoples faces and watching them run off the road gaucking as i go by, just my opinion though, my pa inlaw gits his kicks on the strip and he won't drive it unless it has rust holes all over it go figure, he says he turns enough heads at the strip he don't need the street.. oh and one more thing, a fellow at sunset racing in lubbock a few years ago was running a 68 trailing arm set up with 10.5 slicks and a 555 stroker pushing gobs of hp and tq, he spent a bunch of money to have the truck backhalved and 4 link installed with about 15.5 slick witch is really about 19 in wide or more, any ways he gaind a whole 1/10 through the quarter and a hole in his pocket. its hard to beat the truck arm suspension thats why nascar still uses it and yes it was designed around our trucks layout. id just get a reinforcement kit and some 7.5 bs wheels and run the tires you have....

[mnunn454]

Originally Posted by Robznob11

the low down desk top drag says ill gain 1.5 tenths by going from 3.73 to 4.10 and anothet .5 going to a 4.56 after that i start loosing , 3.07 is a quarter of a second slower than 3.73 this all assuming a 3600 lb short bed with 15 wide 30in tall mild race tires an th400 behind a 496 stroker pushing 630 hp and 640 lbs now the engine has 450lbs at 2000rpm and shifts at max witch is 6000rpm max tq is at 5500 max hp noses over at 6000 rpm.....

Sounds like a great answer. I'm more of a try it and see kind of guy.

smoknbarrels: Were it me, I'd go with the lowest gearing/highest torque combo that meets your highway cruising needs. Then, if it spins too much in first at the strip, then I'd increase the tire size and change wheel back spacing as required until it finally bites well.

Once you're at your limit in tire size and then if the tires are still spinning at the top of first, I would advance my 1-2 shift by 200 RPM at a time until I found the best balance between 1st gear overspin and 2nd gear "pull" or strain. As long as the motor doesn't drop much below your peak torque curve in second, you should be fine.

Regarding rear end setups, I'd would not dump the stock rear end setup and go with a 4-link just to solve tire clearance issues (unless I was building from scratch anyway). That's a pricey solution for that particular fix, IMO.

Robznob11: Sorry, I'm not up on the latest gizmo's. What kind of software did you use to model your ET comparisons? Is it on-line (I hope)? If not, was it cheap?

Thanks.