C4 External filter

I have a 65 pony with a c4. Had a external filter & cooler on it for 20 years. A local Trans shop told me to never use the filter because they claim it wont flow enough & the bypass inside the trans will

kick in & just recirculate inside the trans. I was told that if about a quart ran thru in 20-30sec it would be ok.

Haven't had a problem in 20 years. Any thoughts?

I see no reason to run one honestly. only trash it will collect will be from the converter and if it pukes it wont matter anyway.

I use  fuel injection filters , a couple 5/16" compression  fittings and you good to go
 Frank

Any restriction in the cooling lines, including an inline filter, will restrict converter charge oil creating reduced efficiency and increased heat build up.