best97obs
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and will I need to replace valve springs, lifters, rockers, etc?
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So, there are documented dyno results with upgraded aluminum heads, higher compression, and a more aggressive XE274H cam only making 415hp... but you are saying stock vortec heads and a 270h cam will make the same power? Do you have a dyno sheet showing that?It is not hard to get 400 hp with stock Vortecs. A XM270HR will get you there with long tubes and decent exhaust.
You can't buy stock replacement heads for less than $600... I'm not sure what you are looking for here. A set of assembled Dart S/R heads like the ones used on the engine that comp used for their dyno pulls costs $800 EACH. For IRON heads.got recommendations on some good heads that aren't over 600 dollars?
There is documented data of a 330 HP 350 HO engine upgraded to a GM Hotcam and 1.6 rockers making 401 hp and 428 tq with the crappy flowing Mexican 062 heads that came on that engine. The comp cam I mentioned is slightly more aggressive for the same 0.050" duration as the hotcam.So, there are documented dyno results with upgraded aluminum heads, higher compression, and a more aggressive XE274H cam only making 415hp... but you are saying stock vortec heads and a 270h cam will make the same power? Do you have a dyno sheet showing that?
Comps own results show that with 9.25:1 compression and Dart S/R heads, they only made 342hp with that cam.
https://www.compcams.com/xr270hr
Comps dyno sheet for the 274h shows it makes about 20hp more than that cam, although their dyno sheet looks a bit odd... almost like valve float or something weird on the top end with the curve flattening out and jumping around above 5k rpm.
https://www.compcams.com/xe274h
You can't buy stock replacement heads for less than $600... I'm not sure what you are looking for here. A set of assembled Dart S/R heads like the ones used on the engine that comp used for their dyno pulls costs $800 EACH. For IRON heads.
The skip white china casting aluminum heads are $860 for the assembled PAIR. Setup with decent valves and Comp springs for a hydraulic roller cam.
https://www.skipwhiteperformance.co...minum-heads-64cc-straight-plug-nkb-274_95131/
The AFR enforcer castings that have been torn down and assembled with the same upgraded valvetrain is $1120 for the PAIR.
https://www.skipwhiteperformance.co...evy-350-383-65cc-straight-plug-274-afr_95253/
Both have smaller chambers than the stock vortec heads, so they should give you a decent bump in compression, which will help with overall power.
What L31 is saying, is that stock vortec heads and the 270h cam will give you plenty of power and be VERY usable in a truck. It WILL NOT get you 400-450hp, because you would need a more aggressive cam and need to rev the engine higher for that. You would be shifting the power band higher up in the RPM range.