stock radiator trans cooler for 4r70w pressure drop

[spap]

Hey everyone, I'm running a 4R70W trans and I am just running a large plate and fine trans cooler bypassing the stock in radiator trans cooler, but driving around today in about 85 degree weather the trans temp got to 190 to 208 degrees and I want it to run cooler than that.

Would it be OK to connect it to the stock radiator trans cooler? I'm worried about pressure drop. the transmission lines from the 4R70W are much larger than the stock bronco in radiator cooler lines.
I ran it that way with my C4 but the trans lines were the same diameter as the in radiator cooler.
Thanks