Is Part 'a" of the AD 80-04-03R2 is applicable on all model of engines with suffix "T"

Part "a" of the AD 80-04-03R2 suggest to replace the upper exhaust valve spring seats with P/N LW-16475-KLI and the exhaust hydraulic lifters with P/N LW-16586 in accordance with AVCO Lycoming Service Bulletin No 435B. I have engine with S/N " T" as a suufix, I want to ask , is this AD's Part "a" is applicable on my engine or not, rthough I dont have the SB status of his engine, guide me.

Frequently Asked Questions: 

80-04-03 R2 Para a says "in accordance with AVCO Lycoming Service Bulletin No. 435 dated March 17, 1979" so I am not sure about SB 435B.  

SB 435 3/17/79 says "MODELS AFFECTED: All O-320-H Series engines with serial numbers up to and including L-6182-76 and reman. engines shipped prior to March 19, 1979" I have read through the SB and nothing is said about a suffix of T in the S/N.


The AD Does refer to the T suffix in para  c3 and the Note following that para about the T having larger lifters but it is not clear how this effects applicability of the AD

I would suggest contacting Lycoming for help.