Na,I think the block should hold up for awhile.
Just keep an eye on things,check for loose bolts and nuts,keep good oil in it and change it when its do.Check out the rockers and pushrods occasionaly,even though your runing a hyd. roller.Check out the balancer and pulleys,if you get any wobbles,fix them.
If it makes you feel better about it I know a guy that raced in FFW spring break shoot out about a year back,and he was runing a 347 Mexican block,and spraying a 400hp shot on a plate.They were having alot of problems else were,but the block has held up.
One thing I think you should consider is going to a single plain intake,you would really pick up some mph and et.