i have some ported 5.3 heads and was wondering if i could just drop in some 2.00 in valves in place of the 1.89 in or should i just go ahead and do 2.10 in valves? and what kind of valves do i buy cuase the 5.3 valves look differint from the 5.7s valves
what shold i do help thanks there is a chart below


Casting Number 241
LS1 / 5.7L Passenger Car and Corvette
97-00 P/N 12559853
01-03 P/N 12564241
Material: Aluminimum
Combustion Chamber Volume: 66.67cc
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 2.00 inches
Exhaust Valve Diameter: 1.55 inches

Casting Number 706 or 862
99+ 4.8L Truck P/N 12559852
99+ 5.3L Truck P/N 12561706
Material: Aluminimum
Combustion Chamber Volume: 61.15cc
Intake Port Volume: 200cc
Exhaust Port Volume: 70cc
Intake Valve Diameter: 1.89 inches
Exhaust Valve Diameter: 1.55 inches

 

anyone?

 

???????????

 

I recommend upgrading to 2.02" intake and 1.57" exhaust valves. These will fit nicely onto the factory installed seats and they also fit nicely into the 3.90" bore. Larger valves will require installing larger seats and that gets into some buck$. If your on a budget, then install a 2.0" intake and go have some fun.
What size cam are you planning? Valve/piston clearance could be an issue with larger valves.

Good luck,

Richard

 

okay so i could just install 2.00" intake valves without any kind of machine work being done? and i plan on running neither a TR 220/220 or TR 224/224 my bottom end is stock 98 LS1, also this engine is going into a S-10 blazer, i will have full bolt ons and true free flow duals..................

 

You would need a valve job, but the factory seats could be maintained.

 

how much would that cost? and would there be much HP gain?

 

It'll cost between $275-$300 to properly seat the valves. That also includes cleaning, surfacing and new valve seals.
Yes more power will be gained, but I can't quote numbers.

That S10 sounds like a ton of fun!

Good luck,

Richard