???? for the motor heads

just want to get a few things done before I di I need to get so info from the mopar guys...some may remem. I'm putting my 340 back in but made some changes and found some things out..
old set up
340 30''
dome top pistons on h beam rods
comp cam 306 555/555 magnum cam
j heads the flow 240/140 @500 adj 273 rockers
x-cel intake/950hp
1 5/8 headers
mopar dist. locked out
727 rev. val body/9 1/2 dyn (4500/5000)
4.57 gears with 29.5/10.5
car ran a best of 7.70 @89.9mph and 1.77 60'
new ss springs and mp drag shocks outy back comp 3 way up front

when I took the motor apart I saw that the chain had a lot of slack in it for some reason,got new chain same thing.
now I took the block to get checked out bores where out from top to bottom for some reason and the rings had anywhere from 20/35 thou gaps just in the top rings....so i started over and I'm doing it myself for fun and to learn things...anyway here is the new build
same block cheked and re honed to spec340 30''
same dome tops (about 11.1 comp) and rods
comp cam xe282 520/540 lift 282/290 and 244/252 @50
same heads 240/140@500 new 1.5 roller rockers
same intake x-cel may gasket match
1 5/8 headers and carb
727 rev val 9 1/2 verta 4500/500
4.57 gears and 27/10.5 qtp this time out
add a timing chain tensioner to it this time and it seems to work great
now my ??? are on the carb what jets should I start out with and should I run the power val's...my carb is list # 80496 but I dont think my air bleeds are the ones you can take out and change from looking at them..also what timing should I set this thing up on thanks for any help sorry so long:cheers: