hot98z28

I just wanted to post my experience with 243 heads off a gto. They are worth it as a budget head i heard many people say no unless ported. But the gain in hp is major to headers the car pulls at any speed its an a4 98 z28 with boltons and vig stall before it wasnt good at 40 rolls but now thats my favorite roll speed. Engine sounds deeper too. I will be getting a custom cam this year and maybe port the heads sometime next if funds are avaliable. Just wanted to post my opinion on 243s.

Felix C

Stock 243s have a touch more compression, 10.5 vs 10.1, and slightly better flow if using the stock camshaft. Not sure why you are feeling so much extra power.

hot98z28

Mine has the triangle under the plugs i heard thats good for another 5 or so hp. But my tunner added a little more fuel without hooking up the wideband but i asked him to check. He was surprised at how much more fuel it needed he said he didnt think those heads would flow that much more.

Felix C

Stock camshaft under .500" intake lift. 243s flow gradually better past .300" so not much of a gain.

The only 243s which might show a noticeable benefit are the ZO6 with lighter valves to rpm more and quicker.

The triangle is a casting mark. Nothing more now 243s might flow better in stock form than 799s.
A 243 is a 243 unless ZO6.

hot98z28

Mine had 806s. All i know is i told my tuner if thats how 20hp feels Like i cant wait for 100. He was impressed that it pulled like it did even on nitrous tune. I did it since i was replacing lifters.

Felix C

241s do flow somewhat better than 806s although both used on LS1s

243s are believed to flow somewhat better than 799s although both are the same type of head.

The above applies only in stock to stock comparo.

Going from 806 to 243 is probably noticeable as 1998 ls1 engines have a stronger camshaft than later LS1 so you can use some of the 243 benefit. Of course, you have the Ls1 intake still on? which is a downer if so.

kinglt-1

iTrader: (26)

You must have sensitive feelers to be able notice 15hp like that. Either way good deal.

hot98z28

I have the ls6 intake lts, catback stall, Which might have helped the heads, did the ho truck coils at the same time. It pulls real good in second. Anyway my tuner and I will be spacing out a cam soon. It ran 12.8 before with the tune being off a bit. I'll do a run to see how much of a difference heads made.