[BTK]

good eve gents....looking through facebook for sale stuff..i came upon an ad for a th400 and got me thinking...again.
I was seriously thing about a 700r4 for my project...however the 400 is stronger....which has me wondering..with my 30 inch tires what would be the outcome of dropping to a low axle gear combined with 30" tires and a stout 468...would it "almost" be like a 4 speed....400s are hard to come by up here....ide like to lean this way but would appreciate some advice..i know there's a fella here that has a wagon coupled to 496 and 700r4..and very happy however to be built up to hold would be cash crazy here
thanks bill...500hp

 

[bracketchev1221]

Are you saying you want to go a 30” tire and something like a 3.0 gear for highway? Low gear Is still actually a higher number but from what it sounds like is that you are trying To have the effect of overdrive. Anyway, the downside to this is that although it’ll have low cruising rpm, it’ll be a slug accelerating as well. The benefit of an od trans is that it has a better first gear for accelerating with an average rear end gear and works like a normal 3 speed until its time to cruise and the next drops into fourth.

 

[mrpaticular]

What do you consider a stout engine?
Are you using all season tires?
In a street application a 700R4 can be built to handle power. Get rid of all the internal plastic parts.
Even a properly built TH350 can handle a lot of power and saves about 10 HP in parasitic loss and weighs much less than a 400.
You just need to decide what your primary use is for the car.
Then, this forum can be more help.

 

[cage2592]

I was in the 4spd decision last year as well. But I was going TH350 and GV OD unit as I already had the TH350 professionally built. I drive 96km round trip to work on HWY and was looking for a better cruise RPM. I decided to stay with the TH350 and installed a 3.00 rear gear in my 9" rear to get 3000rpm at 128kph. I have a lot more HP/TQ than that though. I may still throw in a GV some day.

And if you haven't used or heard about it, look at this site for all your CALC comparisons Gear Calculator.

Mike

 

[Stokerboats]

700 would be my last choice unless you enjoy the bog between gears. 2004r is a much better transmission if you require overdrive.

 

[BTK]

thank you for the replies so far....i guess im trying to get the best of all worlds..my tires are 30"...i can get this 400 relatively cheap already built.....too much $$ to build a 700...dont want to stop at every gas station to my journey at $4.60 per gallon..i believe with 500/500 hp/tq i can get this car going from standstill...just dont want to go too low in gearing...purpose of the car is general cruising..no track ever and dont want a g.v. overdrive...tires are mickey thompson sr..30x15-20
remember i live in Canada and everything is far more expensive