Notices
GM Engine & Exhaust Performance EFI | GEN I/GEN II/GEN III/GEN IV Engines |Small Block | Big Block |
Sponsored by:
Sponsored by:

243 or 821 or 823 for forged 6.0

Thread Tools
 
Search this Thread
 
Old 04-19-2022, 07:21 PM
  #1  
TECH Fanatic
Thread Starter
 
06murder's Avatar
 
Join Date: Aug 2010
Location: ludowici,ga
Posts: 1,698
Received 7 Likes on 6 Posts
Default 243 or 821 or 823 for forged 6.0

What would be the best head for a forged 6.0 it has summit pro ls pistons and rod in there flat tops, building nitrous engine!3-400 shot
Old 04-19-2022, 08:54 PM
  #2  
DuNnO
 
RDF1's Avatar
 
Join Date: May 2018
Posts: 1,086
Likes: 0
Received 454 Likes on 367 Posts
Default

832s and 831s make good power. Whats compression with the pistons you have?
Nitrous cam or N/A cam?
Old 04-19-2022, 09:06 PM
  #3  
TECH Fanatic
Thread Starter
 
06murder's Avatar
 
Join Date: Aug 2010
Location: ludowici,ga
Posts: 1,698
Received 7 Likes on 6 Posts
Default

71cc =10.1 68cc= 10.4 65cc 10.8 61cc =11.5 2cc flat tops. trying to find a good nitrous cam i want max effort! lol goal is deep 6's in the 1/8th
Old 04-20-2022, 05:43 AM
  #4  
TECH Fanatic
 
smokinlmm's Avatar
 
Join Date: Nov 2015
Location: Coastal NC
Posts: 1,753
Received 408 Likes on 320 Posts
Default

799/243 are the same castings as a corvette head with diffrent valves and such. I'd run the 243's, but the others aren't bad either.
Old 04-20-2022, 07:55 AM
  #5  
Launching!
iTrader: (18)
 
ALL ULL C's Avatar
 
Join Date: Oct 2005
Location: IL
Posts: 272
Received 74 Likes on 60 Posts
Default

I think a good rule of thumb and has been most likely documented someone in the www is that replacing a cathedral with a square port even with a drop in compression gains about 30hp, not sure it's 30whp. However I think that is more towards peak and not so sure what the entire curve looks like. Could always mill the square ports to gain some additional compression.
Old 04-20-2022, 08:26 AM
  #6  
Launching!
 
68Formula's Avatar
 
Join Date: Jun 2011
Posts: 290
Received 147 Likes on 100 Posts
Default

Both 821s and 823s are square port. Only differences are the 823s chambers are 2cc smaller and hollow stem valves.
Old 04-20-2022, 07:39 PM
  #7  
TECH Fanatic
 
smokinlmm's Avatar
 
Join Date: Nov 2015
Location: Coastal NC
Posts: 1,753
Received 408 Likes on 320 Posts
Default

If it's in a truck wouldn't the low rpm torque from the 243's help get it up and moving versus the square port higher rpm torque?
Old 04-20-2022, 08:07 PM
  #8  
100% Redneck
 
RedXray's Avatar
 
Join Date: Mar 2005
Location: MAGA COUNTRY
Posts: 2,099
Received 1,331 Likes on 793 Posts
Default

Originally Posted by smokinlmm
If it's in a truck wouldn't the low rpm torque from the 243's help get it up and moving versus the square port higher rpm torque?
It would.

OP didn't post if the truck is going to live on the street. If it's a strip only truck a big stall will cover that low end handicap. A 300 to 400 shot is gonna have to be progressively controlled. Should pull like a freight train with either square or cathedral ports.
Old 04-20-2022, 08:18 PM
  #9  
TECH Fanatic
Thread Starter
 
06murder's Avatar
 
Join Date: Aug 2010
Location: ludowici,ga
Posts: 1,698
Received 7 Likes on 6 Posts
Default

It’s daily for now till I get my wife car fixed, she driving my 16 Silverado right now, it will be street track only soon! It need a new converter right now I think the 5.3 with 200-250 over power it, it falling on it face right before the 1/8th! My cousin saying to run 821/823 on it it would help little on the spinning she does but gain more on top.? Cam I not set on yet tell I figure out the heads first nitrous will be on progressive 2 stages, just want low low 6’s to keep up at east coast truck wars
Old 04-20-2022, 08:55 PM
  #10  
TECH Fanatic
iTrader: (16)
 
01FormulaTA's Avatar
 
Join Date: Jun 2006
Location: H-town
Posts: 1,426
Received 29 Likes on 23 Posts
Default

for your goals no question you run the rectangle port heads with a big converter to match whatever cam you choose


Quick Reply: 243 or 821 or 823 for forged 6.0



All times are GMT -5. The time now is 02:45 AM.