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-   -   th350 build mod (https://67-72chevytrucks.com/vboard/showthread.php?t=228497)

Srubydo1986 02-21-2007 03:30 AM

th350 build mod
 
I had the 350 in my manual truck and it would burn tires off and do donuts with out problems. Im know putting that moto in a automatic i liked the response i got from the manual and i know no auto will do want a manual can but what can i do to a th 350 to make it more racey. I will be change the rear to a 373 after some time is a 308 now.

But like i said what can i do to a th350 to make it more stout for the motor
remember this is a dd street car and will be drivin daily i just want more umf from the tranny (was look at a b&m shift improver kit cost 31.95)

(tranny has to be rebuilt anyway im at about 400 now for that shift kit and rebuild)

Zoomad75 02-21-2007 09:56 AM

Re: th350 build mod
 
I've used a kit called a no-go shift kit. Funny name, but it's low cost and low modification. Bore out a couple of holes in the valve body plate and a couple of other minor tweaks and you are done. Not a full on race trans, but it snaps gears pretty quickly when you are on it (shifting manually). Leaving the shifter in Drive and it still shifts smooth with a new firmness. Nothing neck snapping, Just not a rubber band type shift it used to make.

Keep this in mind, all you are doing is playing with shift quality with a basic shift kit. you aren't really beefing the trans much at all. IF the trans is old and you start hammering on it you might still break something. Heck with the mild 350 in my Nova I managed to shatter a clutch retaining ring with nothing more than hitting 2nd gear hard manually. Bang! second gear was gone. That was with a 350 running a cast iron 4bbl intake, qjet and a very tame cam with stock exhaust manifolds.

boatpuller 02-21-2007 11:08 AM

Re: th350 build mod
 
i'm no mechanic.but i have read where th350's can do alot.people run them with big blocks.it has alot to do with stall converter.i've seen after market custom builders warranty them to 600 h.p.

BADGMC 02-21-2007 01:11 PM

Re: th350 build mod
 
My TH350 has been putting up with 650hp or better for a couple of years now since I rebuilt it myself. Manual valvebody, hardened sprag race, and new alto red eagle clutches with kolene steels are the only things not stock in mine. Most cheaper rebuild kits don't have very good clutches so stay away from them and if you can, replace all the thrust washers in it with torrington bearings as I have been told that this reduces a ton of heat and frees up a bit more power.

Srubydo1986 02-21-2007 02:50 PM

Re: th350 build mod
 
I was kinda looking at this im a b&m fan and never heard bad things

http://www.bmracing.com/index.php?id...t=19&subcat=24

magnethead 02-21-2007 06:43 PM

Re: th350 build mod
 
My question: What exactly is a full-manual valvebody? Does that disable drive and "reassign" it as third gear? I drive my truck (454/400) as a manual every now and then (i do the pedal work like an unsyncro manual- off the gas for upshift and tapping it for downshift to save the clutches) and it's actually kinda fun. and thankfullly, it shifts regardless around 4500 RPM...dont ask how i know.

82c10 02-22-2007 01:03 AM

Re: th350 build mod
 
Quote:

Originally Posted by magnethead (Post 2042509)
My question: What exactly is a full-manual valvebody? Does that disable drive and "reassign" it as third gear? I drive my truck (454/400) as a manual every now and then (i do the pedal work like an unsyncro manual- off the gas for upshift and tapping it for downshift to save the clutches) and it's actually kinda fun. and thankfullly, it shifts regardless around 4500 RPM...dont ask how i know.

no, it is still drive, but yes it would technically be 3rd gear, on the other hand, why do you let up off the gas when upshifting?

magnethead 02-22-2007 09:18 AM

Re: th350 build mod
 
If you've driven an unsynchro'd transmission, you have to match the engine and input shaft speed using something other than the clutch, especially with a wide ratio box. In a synch'd transmission the synchro's do it for you.

might be otherwise known as the "heal-toe" technique.

82c10 02-23-2007 01:35 AM

Re: th350 build mod
 
Quote:

Originally Posted by magnethead (Post 2043191)
If you've driven an unsynchro'd transmission, you have to match the engine and input shaft speed using something other than the clutch, especially with a wide ratio box. In a synch'd transmission the synchro's do it for you.

might be otherwise known as the "heal-toe" technique.

i meant why do you do that in your auto? it will not hurt the trans if you upshift it with your foot still in it, and on the unsynchroed tranny thing, yes, and i have also driven a car that the synchroes were bye-bye in it(for lack of better terms)

magnethead 02-23-2007 08:14 PM

Re: th350 build mod
 
just to have fun. I can hear the clutches screaming if i shift while my foot is still in it and the shift takes forever.

MylilBowTie 02-24-2007 01:24 AM

Re: th350 build mod
 
Full manual valve body is mainly for the track. You have to shift every gear every time. You have to shift the transmission just like a manual transmission but no clutch. That's not to say its a manual now. Just have to shift gears constantly like one.

The reason why your th400 shifts out of first is that it is a over rev protection. You can make it hold 1st gear as long as you want if you install a plug in the valve body.

About the only thing you can do to the th350 is get a higher stall convertor. But it kind of defeats the real perpose of needing one. It also isnt a very good idea to put money into a weak and failing transmission. I would go with a Transgo shift kit/ shift improver after it gets rebuilt.


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