396/375 camshaft questions

Alan Roehrich · 04-27-2008, 08:22 AM

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.

04-27-2008, 08:22 AM	#7
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,116 Likes: 1,573 Liked 1,831 Times in 415 Posts	Re: 396/375 camshaft questions 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. __________________ Alan Roehrich 212A G/S