904 transmission shifting adjustments

I see a few areas that need work. The "hose" used for the forward ATF cooler line really should be solid steel tubing like stock. If you cannot find any, the hose needs to be Heavy Duty hose designed for the heat and pressure that they would see for this kind of use.
Seeing the linkage arm held forward with plastic zip ties tells me that your transmission guy took some short cuts. I don't mean to offend but someone does not know what they are doing. If this is a manual valve body setup, why not just remove the arm? Still, why use what looks like light duty fuel line hose to handle transmission oil that can get to 180 degrees or more?

Also, you wrote......" i need to dyno this thing but i think im putting out around 300-400 horsepower."
That is a pretty wide range to estimate...25%. I didn't see if this was a 318 or 360, the cam or the compression. No matter what, that transmission could get fried to bits pretty quick if you don't get the kickdown sorted out quickly. No engine with more than 180 HP ever was installed with a 904 transmission behind it. Every 340 had a 727 if it was an automatic and they were rated at 290 HP for the 1970 340 six pack, 275 for the 340 4 barrel from 68-71 and 240 HP from 72-73. A stock rebuild on a 904 cannot take the abuse that a 727 can. Even if you are on the low end of the HP estimate, a stock 904 is not designed to take it. Is this a stock rebuild? Does it have a billet drum? Kevlar clutches? Drilled valve body to increase flow? Anti-balloon plate in the converter? What size and stall of the converter?