396/375 camshaft questions

[Alan Roehrich]

The 4/7 swap is legal, so is the 2/3-4/7. What you need to know is that if you change the firing order, you need to make sure your new firing order runs with your header/collector combination. If you have the wrong combination, it will hurt power.

[Geerhead55]

Thanks for the heads up Alan,,, They have'nt picked out a header/collector combination yet. Theres a little more research to do first, but you've deffinately given them something to consider.
Danny Durham

[Alan Roehrich]

Danny, you can go from around $800 or so for a nice set of Hedman step headers, to $1600 or so for a set of nicer Stahl step headers (best 4 into 1 header there is) to $3600 or so for a set of Calvin Elston tri-y headers. For the 4 into 1 headers, a set of SPD or Performance Welding merge collectors is a wise investment. You do not need them with Calvin's stuff. You can run the same header with the 4/7-2/3 swap as you do the stock firing order. But the 4/7 swap is a combination all its own. Stahl has a set of collectors for his headers to work with the 4/7 swap. A lot of people will tell you there is nothing to be had with firing order swaps power wise. But few will argue that they help harmonics. The new LSX engines use the 4/7-2/3 swap firing order. I've found that the NitroPlate coating can be worth 2% on the dyno, and it protects the headers very well, not to mention they pay contingency money. Jere Stahl can help you with steps, tubing sizes and lengths, with Hedman you get what they have.

[Geerhead55]

Thanks again Alan,,, I'm not sure what the budget for headers will be for them. I like the idea of the Stahl headers myself. We'll be doing a lot of brain picking at the Mission B.C. divisional race next month.
I appreciate your input...............................Danny Durham