Late Model Speed 243 CNC'd heads
 

Does anyone have any experience with these heads?

Thinking about getting a set.

The specs are listed as

Detailed Description
New GM LS1 LS2/LS6 243 casting
5 axis CNC machined
Fully assembled
220cc Intake Runner
Intake Flow Rate 305 CFM
Exhaust Flow Rate 235 CFM
New 2.000 intake valves / 1.550 exhaust valves
GM Valve Seals, Retainers, and Locks
Custom single coil valve springs good to ~ .580 lift
Custom engraved LMspeed logo

Thanks

2GOFAST

GM makes several different 243 castings. What part number is it?

I am not certain. It does not have the hollow/sodium valves though if that helps.

What questions should ask of LMS regarding the casting #.

LMS told me they have a CNC shop do the actual CNC work. They do not have CNC machines.

The ones with hollow valves are ls6, so those are ls2 heads

I had them on my setup and they worked out great with my blower and cam setup. Hard for me to compair with N/A setups though, but they are worth the money. Call Ed and talk to him about them, he'll give you any information on them you need. Most places that have ported heads like this are farmed out to machine shops normally. Is cheaper and more cost effective that way. With those heads, cam, headers and 8#'s on my blower I was making 500RWTQ at 3000 RPM's peaked HP around 523RWHP. They are good heads for basic cam setups or F/I IMO.

I would buy them again, and my setups are normally more then just a set of heads and cam.

I have them on my setup with the same blower and pulley that Badmonkey had until he demodded. I have no issues with them, they flow really well and were cheaper than the TFS and AFR's, by about half. Mine came in Livernois boxes with LM Speed engraving on them. I checked the Livernois website, and I believe they are the same as their Stage 2 by the flow numbers that Ed gave me. Mine were worked over to Ed's specs for the blower kit, so talk to Ed and he can get them ported and setup for whatever your specs will be.

I agree. GM has three different LS6 243 heads( 3 diff part numbers) with hollow valves. Two are high flow road racing heads.

243 heads
 

well 243 castings are 243 castings, they do make them with different valves and even CNC from gm those are good entry level heads and im looking at them, Patriots and Livernois - im leaning to the Patriots with the cam ill be running - how big of cam are you going to run? exhaust? they all work together so make sure it all breathes well together

Would there be any negatives in using either of the two 243 road race heads on the street?

One they are very very expensive, Two they dont like low RPM use.

So many other vender's make great street / strip High performance heads.