gears

[72chevyrick]

I have a 66 short bed,has 9inch ford rear,turbo 400,4500 stall,454 with around 750-800 hp,29 inch slicks.have 350 posi for gears.cant get it out of the high 12's..truck weighs 3250 with out me.what gears do you recommend?

[Super73]

Questions...

What is your tracks altitude?
Has the motor been dynoed to verify that hp?
What is you 60' at the track?
What mph in the 1/4?
Have you verified converter is stalling to 4,500 when leaving the line?

[Marv D]

Something is DRASTICALLY wrong. My 3630 pound 66 SWB with only 660HP small block went 10.8's @ 115 in 6000' air, 10.5's in 2500' air. It's a pfhat tire truck and hooks well. Pretty much same setup you have except for SBC instead of BBC (TH400, 9" with 4.30 gear and a 33" tall DOT slick) Unless your spinning all the way down the track,, I think someone stole about 400HP while you weren't looking.

What is your trap MPH

[72chevyrick]

Only 3 runs made.the last one i had severe sputtering off the line then it took off.that was last sat.turck has been setting.havent been out in the shop to work on it yet.had someone tell me they thought the trans was slipping at the end of the track.having back surgery soon,so may be waiting tell around sept to go back out ..if your ever up here come by and check it out..off the riggs about 10 miles east of the 10 fwy

[BR3W CITY]

3 runs with a possible trans issue isn't exactly a good way to gauge what the truck is actually doing....and definitely not worth chasing gear changes until you sort that out.

And post the rest of the info Marv and Super asked for. You could be losing most of your time at the line, or at the big end. Easiest way to tell is to read the numbers.

[71Dragtruck]

So if you were sputtering and maybe trans slipping, why would you ask about gearing? First fix the sputtering, then see for sure if the trans is slipping or if the motor is just falling on its face, once you have all that done and made some solid runs then you can look at trap speed and RPM to decide if a tire size or gearing change is needed.

Also just a FYI I use to run high 12's with a 450hp 396BBC at 4100lbs plus driver in 3600-4000'DA air.

[Marv D]

72 good luck with the back surgery. It's a slippery slope. I've had 3 and a fusion, I'm headed for #4 soon. As you fix one level,, then next in line (above) tends to be overstressed and collapse. It's sort of like this racing 'fun'. The quicker you go the more 'stuff' you tear up.

Get your carb/timing issue sorted out and come out to one of our ADRA races at Wildturd and lets see whats happening.

750-800 is a lot of HP,, tell us a bit about the motor. What was the motor spinning on the top end and what was your MPH on the 3 runs?

[72chevyrick]

thanks MARV.THEY ARE TRIMMING THE vertebrae AND THE DISK,NO RODS YET.I WAS AT THE LAST ADRA,WERE YOU ?THE ENGINE IS A MECHANICAL HILBORN INJECTED BIG BLOCK.WE THINK IT COULD HAVE BEEN THE LINE LOCK ACTING UP.

[Marv D]

Actually I had to skip the last ADRA race at WildTurd. I lost a trailer wheelbearing 2 weeks earlier in Tucson and managed to bubblegum and duct tape the thing together enough to get it home. The 19th weekend was an all out effort to replace the torsion axle and rewire the brakes.

Next Wildturd race is May 21 (a night race) I'll be there with the Nova in SuperPro unless it sells before then.

[Super73]

72Chevyrick,

750-800hp is a lot of power and imo it would take a really well thought out 454 with really good heads\intake and pretty radical cam. Couple that with a 3,250 race weight and once dialed in should go high 9's with out an optimal gear and somewhat close verter.

It would really help us better guage your set up if you gave is more info. I am not saying you don't have a killer 454 but to go high 12's seems waaayyy off.