What would my compression be with 64 cc heads if I order the tsp 408 short block with -23cc diamond dish pistons I wanted to put it in a 2003 silverado 4X4

 

9.2:1
Assuming zero deck and .053 gasket

 

Thanks also would the TFS 220 CC heads be good for bottom to lower end torque for towing etc?

 

The heads yes! The compression ratio...no.

We have sold quite a few sets of the 220 as cast heads this yr. Great budget head at ~ $1700 come with good springs, and a good valve angle also with a cnc chamber.

 

What would be the best pistons to go with? Also would it be bad to do the 421 or 418 combination on the street?

 

i think -15cc Dish wiseco would put me at 10:5:1 right?

 

What is this going in?

 

a 2003 Silverado 2500hd with a 4l80 34s and 4.56 gears

 

Why spend so much on a short block honestly?
The 408 if in a gen3 is the best bet. Itll go in with the least amount of extra expense and adapter harnesses etc.
With such huge tires and such i assume you dont tow and haul but go offroad quite a bit?
If you want low end grunt for offroading etc a 408 will do it, but youd want in the 10.0 to 10.5 max range. Any more than that and you can run into issues with knock down low. On pump gas.
Those heads will make power on anything so id stick with them though.

 

Shoot me an email, we can talk about this more in depth for what you want.

Rpmspeedtech@gmail.com

 

Why not find a low mile lq9 and slap some worked 243 heads on it to get the cr around 10.5:1, and feed it 91 octane. It will be cheaper, and will get good numbers. I tow with my big fat heavy pig all the time, and it tows amazing. It gets **** for gas mileage, but it tows great. Once I get long tubes and a good exhaust system on my truck, I should be able to get 350/350 to the rear wheels. That's not bad considering putting those numbers down through a 4l80e trans, 4.88 gears, and 35" tires.

Short video of truck on the dyno
vvvv

 

If you are staying NA, you do not want anything with a -23cc dish piston.

Keep compression around 10.5:1 and the quench around .040.