What heads for a 496

[Tahoe540]

I am building a 496 for my 20.5 Hallett open bow jet boat.

The jet has been completely rebuilt and has a stainless A, bowl stuffer, inducer and a droop snoop with ride plate.

The parts I have for the short block are
BBC Mark IV 2 bolt block with a stud girdle. 4.310 bore
Crower 4.25 crank
Crower 6.385 I beam rods
Looking at a hydraulic roller with over .630 lift./Johnson lifters and will use stainless rockers

I have never ran oval port heads and the more I read on these heads and what rpm I will be using it for they seem to make really good power.

The heads I am looking at are no larger than a 320cc intake runner as this will not be a high rpm motor. I have seen some dyno videos online that show 290cc intake runner heads make over 600hp and good torque on this size motor.

Square Port

Canfield | WilkesPerformance | United States​

Canfield Big Block Chevy Castings

www.wilkesperformance.net

Round Port

PROFILER SNIPER BIG BLOCK CHEVY 290CC ALUMINUM 24 DEGREE CONVENTIONAL PORT HEADS - PER PAIR - FULLY ASSEMBLED​

PROFILER SNIPER BIG BLOCK CHEVY 290CC ALUMINUM 24 DEGREE CONVENTIONAL PORT HEADS - PER PAIR - COMPLETE
www.westcoastoffshore.ca
They make a 320cc version but I think it might be too big for sub 6k rpm use.

I have always run large square port heads with higher rpm in mind on larger cubic inches from 540-582 and want to size these better for lower rpm use with the smaller cubic inch.

I am open to other suggestions.

I doubt this will ever turn over 5500 rpm with that A impeller and size of boat.

 

[BigJimSportsCamper]

Hello Tahoe540- Below link is for aluminum heads i was running in my 496 GM block. I know am running them on my 582 Merlin Block.

BBC CHEVY 496-572 BRAVO 335 REC. PORT 335cc ALUMINUM HEADS ASSEMBLED BRAVO-274 | Skip White Performance - We have the best prices you will ever find for aluminum heads, rotating assemblies and strokers

OUR BRAVO 335 FULLY ASSEMBLED BBC HEADS. FOR USE WITH HYDRAULIC ROLLER CAMS UP TO 620 LIFT. 123cc COMBUSTION CHAMBERS 335cc runners. This sale is for a set of heads (2 heads). *** IMPORTANT NOTE *** You may add items into your shopping cart but in order to check out you will have to call us. Our...

www.skipwhiteperformance.com

Very reasonably priced. Let me know if you want me to share my build for my 582 cid, 780 HP @6k, 720 ft. lbs of tq at 5K.
Thanks- Jimmy

 

[bocco]

Hello Tahoe540- Below link is for aluminum heads i was running in my 496 GM block. I know am running them on my 582 Merlin Block.

BBC CHEVY 496-572 BRAVO 335 REC. PORT 335cc ALUMINUM HEADS ASSEMBLED BRAVO-274 | Skip White Performance - We have the best prices you will ever find for aluminum heads, rotating assemblies and strokers

OUR BRAVO 335 FULLY ASSEMBLED BBC HEADS. FOR USE WITH HYDRAULIC ROLLER CAMS UP TO 620 LIFT. 123cc COMBUSTION CHAMBERS 335cc runners. This sale is for a set of heads (2 heads). *** IMPORTANT NOTE *** You may add items into your shopping cart but in order to check out you will have to call us. Our...

www.skipwhiteperformance.com

Very reasonably priced. Let me know if you want me to share my build for my 582 cid, 780 HP @6k, 720 ft. lbs of tq at 5K.
Thanks- Jimmy

These look like a screaming deal at $1259.00 for an assembled pair. I'm looking at almost that much to put new valves and springs in my iron heads. If the combustion chambers weren't so big I would give them a shot for sure.