So what the difference between some milled 862s and some stock 243s? Also how big of a difference would the 243s and a nnbs intake do on a 2003 4.8?
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So what the difference between some milled 862s and some stock 243s? Also how big of a difference would the 243s and a nnbs intake do on a 2003 4.8?
Not to thread jack but I'm interested in this myself. I've read that 862 ported and milled will do wonders on the 4.8/5.3. 243 would have to be milled from my understanding just to get back to factory type compression. I could be very wrong but I'm going to have a set of 862 worked and see because they are usually cheaper. Hopefully someone with more knowledge and experience will chime in.
If you can get the 243s cheap then I would probably go that route if your running the cam in your sig. I would think just milling those to get back to stock compression would be a nice upgrade and may be cheaper than working the 862. I would also contact your tuner because if you aren't already you will be pushing the limits if your still running stock injectors. Just a thought. Hopefully some one else will shed a little more light on this.
The reason 862s work well is because they can achieve a higher CR. The 243s flow much better but require a heavy mill to get the compression back to stock.
May also have to worry about ptv clearance as well with 243 if your doing a lot of milling
what you want to spend on a set of 799/243 heads