How much power can Vortec heads make?

Jeff Smith: We wrote about Vortec heads in 2016, and that article spawned this question. The original answer was related to modifying the heads to accept more valve lift. Our original answer combined the Chevrolet Hot cam with a set of these Vortec heads. Our estimate then and now is around 350-375 horsepower.

Why are Vortec heads better?

The L31 Vortec heads have larger ports than the older Gen I cast steel heads, so they outflow the older heads. The Vortec heads are a little bit lighter than the older heads and have a “kidney” or “heart” shaped combustion chamber that is more efficient than the double hump chamber.

How much horsepower does a 350 with Vortec heads?

Cam And ValvetrainAs good as the Vortec heads are for a production-based head, they still poop out at around 350 hp.

What is the difference between Vortec heads and regular heads?

Vortec Intake Valve Seats and Combustion Chamber

The Vortec combustion chamber is a kidney-shaped design that promotes better combustion and will have the spark plug located near the center of the chamber. The regular 350 head utilizes a 90 degree intake bolt angle while the Vortec makes do with a 72 degree bolt angle.

How do I get more lift from my Vortec heads?

What do I need to put Vortec heads on my 350?

How good are Chevy Vortec heads?

GM’s 706 Vortec heads are the cheapest and most effective heads you can use for your 5.3L, or 4.8L, or even some 6.0L LS engine build. … These cathedral offerings come stock with great flow and, unlike many truck heads, smaller factory combustion chambers (61.15cc) that won’t drop your compression into the basement.

What cams work with Vortec heads?

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Jan 17, 2022

Can I use 305 heads on a 350?

I did the 305 heads on a 350 in the mid 80’s, using just plain “smog motor” small valve heads. The theory being that smaller valves work better on the low end, and the smaller combustion chamber will boost compression around a point.

Are 243 heads better than 706?

The 243 head has 2.0″ intake valves and 1.55 exh. The 706 uses 1.89 and 1.55 respectively. The 243 is an excellent head, but losing compression coupled with a larger intake valve in a tiny bore engine isn’t a good combo in comparison to the 706.

Are 799 heads good?

The 799 heads offered the most flow, bettering the 706 heads by as much as 20 cfm at some lift points. The chamber volume on the 799 heads was within 2.5 cc’s of the 706 heads, but the dyno indicated this did not translate into power on our test engine.

What heads came on 4.8 LS?

The LR4 is a 4.8L iron block truck engine that was introduced in 1999. Along with the LM7 and LQ4, they were the first LS truck engines. The LR4 was available in GM pickups, vans, and SUVs until 2007.
…
LR4 Cylinder Heads.
LR4 Cylinder Head Specs
Cylinder Head Bolt Size (2004-2006) (10) M11 x 2 x 100, (5) M8 x 1.25 x 45
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Feb 7, 2019

What LS heads are best?

The LS6 was designed specifically by GM to surpass the LS1 as the best performance head, and it did such a good job that the “243” casting was recycled on the LS2. Aside from the LQ9, which is a copy of the LS6, these are the best performing of the OEM cathedral ports.

What do 243 heads come on?

The 243 heads came on the LS6 engine produced from 2001 to 2006. It was typically found in the C5 Corvette, but it was eventually ported to the LQ4 and LQ9 to meet truck specs.

What vehicles have 243 heads?

The 243 head came on the more powerful LS6 engine from 2001 to 2006, and was used in C5 Corvettes. Later engines like the truck-spec LQ9 and LQ4 used the exact same port design as the LS6’s 243 heads, but had 6 cc larger combustion chambers.

How much horsepower does ported heads add?

Porting the heads will definitely help airflow. You will gain 25 HP over the stock setup.

Are 243 heads Cathedral Port?

Essentially a 243 head with different casting numbers, the 799/243 heads are considered to be the top of the line, factory, cathedral-port offerings. Tested on a flow bench, the 799 head offered right at 249 cfm at . 700 lift on the intake and 191 cfm on the exhaust.

What heads do LQ9 have?

LQ9 Cylinder Heads
LQ9 Cylinder Head Specs
Exhaust Valve Diameter 1.550 in.
Cylinder Head Bolt Style Torque to Yield (TTY)
Cylinder Head Bolt Size 2002-03 (8) M11 x 2 x 155, (2) M11 x 2 x 100, (5) M8 x 1.25 x 45
Cylinder Head Bolt Size 2004-07 (10) M11 x 2 x 100, (5) M8 x 1.25 x 45
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Feb 2, 2018

Are ported heads worth it?

Once power increases from other methods have been maxed-out to a point, head porting can be a great next step to producing another incremental power jump. … Couple head porting with a performance camshaft with a nice high valve lift and there can be some serious potential for higher upper rev range power output.

Does port and polish add HP?

In fact, a good port and polish job adds an additional 10 percent in both horsepower and in fuel economy, so it’s worth it. Start by cleaning the ports and then painting them with layout fluid. Place the high-performance intake manifold gaskets and exhaust gaskets in place and secure them with the bolts or nuts.

Is it worth it to port and polish heads?

But for those of you who don’t know, porting and polishing your heads is beneficial for power and efficiency of the engine. In a lot of cases, because of the increased CFM of the heads, as much as 30 horsepower is typical with good port work.