i have a 1956 dodge pickup with a hoped up 318 and a stock 904 3 speed and a 8.25 inch rearend from a newyorker gears are 245 i get 6 to 10 mpg
tranny leaks like a sive

 

First thing I would do is pull all the spark plugs and check the colour. There could be a trans problem, where is it leaking from? Do you keep the level up?

 

Carb or FI? What performance parts have you added on?

Fix the tranny leak first and go from there.

 

What size tires? That 2.45 gear is not meant to be on a truck. Might be better off with a 3.23 instead.

just my .02 worth.
john

 

8.25 inch rearend from a newyorker gears are 245

 

it got a rv cam high top pistons 30 or 40 over i cant remember hooker headers cherry bombs high tension valve springs edelbrock 650 cfm 4 barrel edelbrock intake and k&n air filter
i keep the thranny filled it seames to leak from around the pump or where the torque converter goes in the tranny
the rearend i have wanted to replace it is from i believe a 1976 newyorker i would like to find a 323 or so with a locker

 

Unless you have a gas leak then an over rich carb is what I would look at first. This will show up easily on the plugs as black fluffy deposits. Check your oil just to be sure your fuel pump isn't broken and leaking into the block diluting the oil and ruining your bearings. It's rare but worth checking if the change was sudden and significant.
Good Luck.

 

Yes,it sounds like the front seal. It's easy to replace,but you have to pull the tranny :-( If you do it,also check the hub on the convertor were it is in the seal.Sometimes a little groove gets worn in.

Did you pull the spark plugs yet? Are you using vacuum advance on the distributor?

john

 

the engine has less than 750 miles on it and carb is new i havent drove it much because im in college i got the truck when i was 12 and drove it to senior prom for its madin voiage so the truck hasnt ben out much but i had the front seal in the tranny replaced when it first started leaking and the seal on the torque converter i had the pump replaced also so i think the last thing could be a worped housing
as for the rearend i was wondering if anyone knew if i could find gears for a 8.25