I have a 71 LS3 402 I did the head swap to 063 close chamber heads. Heads were rebuild with new valves not sure what was all done to em. Stock pistons. I have m-20 4 speed, 373 gears.Right now the cam im running is the thumper 11-600-4 279/296 @50 227/241 .498/.483 107 Im thinking of this cam The Bracket master 00021lk 304/324 @50 221/233 .500/510 115. Can some one tell me if its really worth the cam change? What with these # would i benefit with this cam? Any suggestions of a cam that will go in to this set up with no mods?

Another cam im looking at Lunati 30206 i beleave its a bracket 2. 285/300 230/235 .525/525 has anyone used this cam? Would their be any clearance iss piston valve to retainer in a stock 402bb.

Go bigger , and maybe tighter on the pattern 230ish @.050 and lift of .550ish and lsa 110-112.
FWIW, my '67 w/408 bbc has a crane hyd f/t - 236/246 @ .050, lift .553/571, 110 lsa pulls great with decent vacuum .
You M20 & 3.73's will like a little more cam.
check the voodo line!

In my old 408 I was running the comp cam Magnum 292 with no problems. Stock open chamber heads (other than springs) 10:1 compression, th400 w 3000 stall and 4:10's.

Had power brakes and there was plenty of vacuum for them.