[HWYSTR455]

Originally Posted by Dragncar

The rear is a 59 truck unit with a full back brace. Tubes are like 1/4" wall. Stiff as can be. I bent the tubes forward before I welded the back brace on. I broke several posi units with no brace. And the Mack Williams billet axles were broke after the brace was installed. I have went to Moser 40 spline axles axles, Moser aluminum housing with the big Pro gear set and yoke.
Its hung on Alston 32" ladder bars. 1.43-45 60 foots which is better then the ET MPH show.
The converter is a PTC 9" that will stall up around 5500 but I launch at 3600 RPM.
I never liked the look of the Fab 9 housings unless a full race car.

Oh wow, yeah, you got it covered!

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[wh33lman]

How are you getting the TH350 to shift at 5K+ rpm?
Is there a specific adjustable vacuum modulator that will set up that high...or do you shift manually?
It seems too easy to miss a shift, or push it into neutral if shifted manually.

[steve25]

Most GM 350 and 400 auto's are set to shift no higher then 4800, to go higher the governor needs to changed or moded.

[i82much]

Originally Posted by wh33lman

How are you getting the TH350 to shift at 5K+ rpm?
Is there a specific adjustable vacuum modulator that will set up that high...or do you shift manually?
It seems too easy to miss a shift, or push it into neutral if shifted manually.

governor controls WOT shifts, not modulator. they sell kits to adjust governor shift points.

[straycat]

My 455 + .030 and #16 heads (250cfm/185) solid cam, Offy intake liked 5,500rpm but that was a track car. The 68 GTO 455 with 7f6 and 041 cam like 5000-5200rpm

[Steve C.]

"How are you getting the TH350 to shift at 5K+ rpm?"

One way.......

Valve Bodies
http://www.hughesperformance.com/valve-bodies/


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[Dragncar]

Originally Posted by wh33lman

How are you getting the TH350 to shift at 5K+ rpm?
Is there a specific adjustable vacuum modulator that will set up that high...or do you shift manually?
It seems too easy to miss a shift, or push it into neutral if shifted manually.

Who are you directing the question at ? There are plenty of valve bodies and kits available. You can even drill some holes in the stock separator plate and remove some steel balls and get it done.
Trans Go makes great kits. Myself, I run a trans brake.

[pastry_chef]

Originally Posted by wh33lman

It seems too easy to miss a shift, or push it into neutral if shifted manually.

Many use an aftermarket shifter that helps.

[Half-Inch Stud]

How does a hydraulic Trans EVER Known the Engine RPM ? Ask the Governor

[Willy Lump Lump]

TH400, shift to 2nd manually at redline then slide it into D and let the tranny have it. If you can get to the strip, try different fairly low launch rpms, shift methods, and shift points and let your time slips be the guide.

The secret is only change one thing at a time and make notes.

As an example, launch without increasing RPM. Then increase launch RPM in increments until you're 60 ft time stays the same. Finally use the next to the last RPM to launch.

Hope this helps.

[sdbob]

+.030 455SD. Stock as cast SD heads,stock lift,duration cam,stock pistons,stock lifters,stock pushrods,stock valves, stock springs, stock ignition. I've tried different shift points. Seems to like 5400. 12teens 110 best at 3700 lb car weight.ive tried 4.56,4.10 and 3.73 gears. I couldnt get the 4.56s to work to violent with 9×30 slicks. I'm just a backyard guy learning as I go.

[Willy Lump Lump]

Wow you got a super duty too. The car that performed best with the shift method I described was a 1970 ram Air 3 all cast iron. Cam was a little warmed up but not so much as to cause power braking issues. It pulled 15 in of vacuum which is what you should be getting. It had a turbo 400 and a 355 gear.

Yeah I wouldn't go too nuts with the gear. I found that a 390 gear gives about red line in a quarter. I would recommend a 355 or 373 if you're going to drive it on the street. Doesn't sound like that's the case.

[sdbob]

Well found block many years ago completely by chance in a junkyard. I could not believe it either for $35.00,rods,pistons and distributor. Put engine in a junk 2nd gen. John Herslow recommended the 4.56 gears. He was NHRA record holder in E/SA.

[Skip Fix]

RAIV heads on 455 stock rods 6200.

[Willy Lump Lump]

What was your RPM at the quarter mile with the 456 gear?

Sent from my T767W using Tapatalk

[mgarblik]

The stock 455 with 6X heads I took out of my 62 Catalina was done making power at 4800 RPM. Shifted it around there. It had a 65 Tri-power on it and I think an 067 cam. Decent torque idle to 3000 RPM. I was happy to replace it.

[sdbob]

That was 1980s. I would launch, 2nd would come as quick as I could shift( probably tire slip),then 3rd. I would keep rpms below 6200. I believe he was saying the 56s would get the car moving quicker. It was violent I'll say that.

[Skip Fix]

I tweaked the governor in my TH350 to shift at 600 with a B&M kit.

[glenn911]

my current car i have never tracked. but i shift it at 4800 cause it does'nt pull hard past that. i did track a 400 in the 80's with 3.08 rear and it was at the 6000 rpm that it stopped pulling at in 3rd at end of 1/4. a swap to 3.73 put me into 4th, but i dont remember rpms at end of 1/4.