HELP with BLOCKING in sql server

 HI Experts- 

Need help with heavy blocking on SQL Server Database.

Any Select or update on table A is causing blocking ..then users get timeout in application

• UPDATE on Table A ran from spid 51 run for 30seconds-1 min and then
• SELECT on Table B ran by spid 52
• this causes Blocking and run for 1-2 minutes then users get timeout in application
• SELECT is coming from a View—its not a fast view but getting 3 million rows in <90seconds
• and then whoever else uses the table gets blocked and soon ....
• sometimes no blocking and then all of a sudden timeout due to blocking

FYI:

• Db size 43GB
• Table A is heavily used ...1Million rows
• no missing indexes, no un used indexes, no duplicate indexes
• Index and update stats jobs run every night 2am
• Max dop, Cost of threshold parallelism  are set 8 and 50
• database update stats =on and asyn true
• READ COMMITTED is the default isolation level
• Tempdb files are configured according to number of cpu
• other non-heavily used tables run fine
• full and t logs are running fine
• CPU is 16 core which is huge for this sql server
• memory is 64GB
• SSRS is running in same machine (assigned sql server 80% of memory)

Anyone had similar issue? please advise

Things I tried is to make 1st select query faster but that is the max It could run and I ran out of options.