T-max reciprocity

Nothing easier than to look at manufactrurer specs..

Leslie Stroebel, in his View Camera Technique; "...Reciprocity-law failure may appear as a change in density, a change in contrast,... compensations in failure may involve the use of filters and modifications in exposure and development of the film..." He gives the Kodak recommendations table for general-purpose films (publication F-5), with this corrections:

For 1 sec. of exposimeter, apply a 2x factor, AND reduce 10% developing.

For 10 sec. of exposimeter, apply a 5x factor, AND reduce 20% developing.

For 100 sec. of exp., apply a 12X factor AND reduce a 30% develop.

Phil Davis ("Beyond the zone system"), consider this Kodak corrections excesive for normal films...

Ansel Adams also have in his "The negative" the same Kodak table, and recommend to test before and to preserve the densities of lower values in the negative, overexposing a bit -when doubt-.

It looks that you have to change a bit the development... Test it...

Hope this helps, good luck,