How much HP does 243 heads add?

A stock pair of 243 heads can gain about 20 hp on a bolt-on LS1. Since you already have a cam, you might see a bit more. If your budget does not allow a full porting job, don’t sweat it, just swapping to 243 alone will be a big help.

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.

Are 317 heads better than 243?

According to Internet folklore, the 317 heads used on the 6.0L truck engines share the intake port design with the 799 (243) heads. The 317 heads flowed more than the 706 heads by as much as 20 cfm at some lift points. The peak flow numbers differed by just 7 cfm at 0.700 lift.

What heads are better 706 or 243?

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.

Does porting heads add horsepower?

How much HP does a port and polish give you? Head porting is probably the single most critical piece of adding HP. you can gain 20-30 from a really good port job.

Are LS3 heads better than LS2?

The LS2 has 6.0L of displacement, and is technically was the first Gen IV Chevrolet engine. The LS3, on the other hand, has 6.2L of displacement and is also Gen IV Chevrolet engine. The LS2 heads were a slight step up from the LS1 heads. To no one’s surprise, the LS3 heads are better than the LS2 heads.

What vehicles did 243 heads come on?

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 can porting and polishing add?

Don’t expect huge leaps in horsepower; results obviously depend on the original state of the cylinder head and the quality of the workmanship. If you believe online forum chatter, LS1 cylinder heads can give anywhere between 10 to over 50bhp extra from a port and polish, so it is by no means a linear process.

How much HP does 243 heads add? A stock pair of 243 heads can gain about 20 hp on a bolt-on LS1. Since you already have a cam, you might see a bit more. If your budget does not allow a full porting job, don’t sweat it, just swapping to 243 alone will be a…