cmcolfax

OK, so I just picked up a 5.3 block that has been bored to 3.898 as the start of my 247/5.7 build for my Suburban

Seller is throwing in a set of 862 heads.

I also came across a set of 241 heads.

I know everyone talks about the vaunted 243/799 heads, so what are your thoughts on using one of the other two sets?

I believe the 241's use the same 2" intake valves as the 243's.

The 241's combustion chambers are +/- 2cc larger while the intake runners and exhaust ports are slightly shorter/smaller.

All of this "matters" the big time LSx guys building them for F-bodies and Vettes looking for HUGE how numbers and top end.

I question how much they would make a difference that would make in my Suburban build.

Keep in mind, the Burb is a DD and part time tow rig.

I'll be running stock crank, stock rods, flat top pistons, Comp trunion upgrade, Blue LS6 springs, stock rockers, new 7.4" pushrods, new Delphi lifters, a cam in the 208-214/208-214, 108-114 LSA range, shorty headers, Flex Fuel injectors, and likely a TBSS intake.

Drspencer

iTrader: (1)

cmcolfax

Frony research I expected my CR to be in the 10.x : 1 range based on the flat tops, larger cam and the CC size of the 241/243/799.

Don't the 862's have an even smaller CC and also the smaller intake valves? I don't have the comparison info in front of me.

I'm on my phone, I'm exhausted, it's been a long day between work, hurricane prep and finishing putting the front end of the POS back together.

Work comes early at 0400 again tomorrow.

Look forward to more feedback .

CMC

Drspencer

iTrader: (1)

cmcolfax

This is who I want to use to do the machine work , the assembly work that I can't do, and lean on for guidance based on what they find.

http://centralvirginiamachine.com