11-15-2020, 03:40 PM
Join Date: Dec 2016
Here is my experience , the early 03-05 blocks are good to 4.08 (depending on core shift), I've gone as big as 4.09 on an 04 block.....it did crack after 1k-1200(been a few years since that build) the 06-08 blocks are good to 4.06(again depending on core shift)
I've done a quite a few 407/410ci (4in boreX4.05/4.08 stroke) some 408ci(4.03 bore x 4.0 crank) and the grand daddy of all 5.7s 445ci (4.06 Bore x 4.30 stroke) and a few others in-between
There are no off the shelf Hemi pistons for anything between 3.957 and 4.055, Dimond Pistons does have a program for 4.0/4.030 that they were doing for Arrington before they sold and closed down in VA, PWR out of Alabama also bought a few sets(not a lot of love out there for PWR)
The trick is SBC or Ford flat tops, For the big dollar race stuff Gibtec or Racetec are your go to suppliers
Now for the None $$$$$$$$$ builds Icon (Ford Application) IC613-std or IC613-030/IC613-060 (.030/.060 over bore) is the best one to use, it's a none offset true flat top [piston with a 1.09 Pin height so it works well with 4.05 crank and 6.125 rods , end results in a -.012 dry assembly deck height,.(006 wet assembly) with Eagle heads and .040 head gasket gives you a piston to head clearance .052-.046 , tight fit, leaves you in the 11/11.5 to 1 compression range with eagle heads.
The 4.08 Crank build you need to use the same Icon Pistons and a 6.10 C to C rod ,it gives you a Deck height of -.022/.016 . you can use .030 head gasket to get you in the 11+ to 1 compression.
Issues with both of these and any other lager then 3.957 bore 5.7 is Head gasket , you need a custom gasket ,Cometic. the 4.10 bore gaskets will leak on the 5.7 blocks because the larger bore gasket is designed to be used with the 6.1/6/4 style deck water passage openings.
05 GTxtreme [email protected]
, Not bad for a 426Ci NA 4000 lbs truck ,
04 SLT [email protected]
( I know there's more, stay tuned)
04 [email protected]
138mph , not bad for a 441ci NA 4000lbs truck.