I have a 98 trans am with 806 heads. As we all know these are the worst flowing out of the bunch.. while the heads are off because im changing head gaskets due to leaking.. I was interested in changing heads. I plan to pickup a ls6 intake down the road anyways so im asking what heads would be best for me. the 241s or 243s, can someone explain what cars they are off of and what flow the best? I want to know if its worth upgrading to either of these heads and what kind of power people are making with them and cams. Thanks

 

The 243 heads are the best if you are looking to just swap on a stock head. 243's came on Z06's, CTS-V's, 05-06 GTO's/Trailblazer SS, and 08-up 4.8/5.3L trucks. 241's came on late 00, 01, 02, 03, & 04 Camaros, Firebirds, Corvettes, & GTO's. The 241 heads are really only marginally better than the 806's, while the 243's have better flow and smaller combustion chamber(increases compression). The 241 heads may gain about 5HP and the 243's about 15-20. There is also the 799 casting, which is the same as the 243.

Keep in mind that you will also need to get centerbolt valve covers and coil mounting brackets to swap to a newer style head.

 

So I shouldn't bother with 241s is what your saying. Are you saying the 241s would be around the same as what a bolton car with a cam would put down through 806 heads?

 

Swapping to 241's is not worth it, they would gain hardly nothing over the 806.

 

this is how I have been readin about heads

806 < 853 = 241 < 243 < 5.3L < any other aftermarket head.

Your goal should be to know what the heads flow cfm, then match your throttle body, LS6 intake, Heads and then a healthy cam to help those heads flow that CFM. More cfm, more horsepower.

However, if you get anything that is 99+, you need to make sure you get centermount valve covers too. Check your current heads. If they are early LS1's, chances are you have perimeter style valve covers and will need the centerbolts for any upgrades.

I feel your pain, I am trying to mod a 98 as well. They seem harder then anything else on the market.

 

Yea the valve covers and packets would be different thats why I don't want to bother. What would you guys say if I could get a good polish and port job done on my 806 heads for $200? Would you say that is worth it then, and if so how much power is that usually worth?

 

IDK, I got some 241's flowing 300 cfm through a CNC machine on the heads and LS6 intake. Again, just get everything matched, port matched, goal matched, cfm matched so you have a good shot of accomplishing the torque/HP numbers you're looking for.

Decide what you plan on using your car for, then go from there. If you want a track only car, go for the MS4 or some huge cam and launch at 5K rpms. If its a Daily Driver, then go for something that redlines around 6-7k and maintains some torque as well as decent horsepower for driving around town.

 

I already have my 228r cam with me, everything is here I was just wondering if since my heads are off I Should change them.. but I think im going to keep it as is for now.

 

If you already got your heads off, either go find some aftermarkets to strap on or go pickup some 243's for good price. Now is the time for upgrades while you got it tore apart.

Personally, if I had the money I would find some aftermarkets. If I were on a budget, go find some 243's. Either that or break out the dremmel and start opening up those ports on yours if you decide to keep your heads. Me, Im chaning all my stuff out. Heads, cam, intake, throttle body, oil pump, timing set, injectors, everything. It should be just like a new engine when I am done.

go find some heads man, now is the time. If anything, go find the 5.3L stage 2.5 heads.

 

I also have a 98 and have a TR224 and i picked up a set of 243 heads, that were freshend up by LME and have comp 918s with valve covers and coil brackets for 600.00 shipped, i might get some port work done but that is a pretty good deal with all the hardware. IMO