Thread:

BBC Heads need to know

Can you or someone tell me the valve size, Intake, exhaust and combustion chamber CC on the folowing rec. port heads? And if any of the three will not work on a Gen IV block. Broke d--k cant afford aluminum but I can get first two for a good price. Cast# 14096188 Cast# 14097088 Cast#6272990 Any help would be great. thanks Don ,AKA Wild Hair

From http://www.mortec.com/bbc.htm:

14096188...70-71...rect...OPEN...454 service replacement, also used on later Mark IV LS-6, LS-7 and 454 HO crate motors, 116cc chamber


14097088...91-up...rect...OPEN...Gen.V 454/502 HO, 118cc chamber

6272990....70-up...rect...OPEN...454 service replacement, used on some MKIV crate engines, 118cc chamber

thanks for the info & web site Now to decide what set to get, but for the money, more than likely the 188s. Think they will work good in 12 to 1 468 with 630 lift solid and 2 650 DP on tunnel ram? MSD of course.

Originally Posted by Wild Hair

Can you or someone tell me the valve size, Intake, exhaust and combustion chamber CC on the folowing rec. port heads? And if any of the three will not work on a Gen IV block. Broke d--k cant afford aluminum but I can get first two for a good price. Cast# 14096188 Cast# 14097088 Cast#6272990 Any help would be great. thanks Don ,AKA Wild Hair

The 188 replaced the 990 casting, use either of those but I would not suggest trying the 088 on the mkIV block. I think that valves would have been 2.19" and 1.88" on all three to start.

What is the problem running Gen v heads on a mark iv block. I ask beacause i too can get some 088 heads for cheap but all i have is mark iv blocks.

Originally Posted by 67hallett

What is the problem running Gen v heads on a mark iv block. I ask beacause i too can get some 088 heads for cheap but all i have is mark iv blocks.

Also Barry, can you go the opposite? Can you run Mark IV heads on a Mark VI??

Originally Posted by jrork

Also Barry, can you go the opposite? Can you run Mark IV heads on a Mark VI??

According to the GMPP catalog, all three head versions(Mark IV, Gen V, Gen VI) will work on the Gen VI block.

Originally Posted by Oldsquirt

According to the GMPP catalog, all three head versions(Mark IV, Gen V, Gen VI) will work on the Gen VI block.

Thanks squirt. Appreciate it.

Originally Posted by P-Money

From http://www.mortec.com/bbc.htm:

14096188...70-71...rect...OPEN...454 service replacement, also used on later Mark IV LS-6, LS-7 and 454 HO crate motors, 116cc chamber


14097088...91-up...rect...OPEN...Gen.V 454/502 HO, 118cc chamber

6272990....70-up...rect...OPEN...454 service replacement, used on some MKIV crate engines, 118cc chamber

I would do more checking around on the numbers, ls7 heads are 627 2990 G M 1T block 14015445. front tab T0118 XCH. this long block i bought in early 70s and still in the crate waiting for the right boat. check more around on the net, and check again. most of the time there not right. hit the net and buy a book called how to hot rod big block chevys, printed in 70s and in the back will list all the info you need and chevy part numbers from then.