396/375 camshaft questions

SSDiv6 · 04-24-2008, 09:44 AM

Quote:

Originally Posted by Geerhead55

Thanks for the replies, fellas. Strange only 2 replies with all the 396 racers out there. I hope it was'nt too touchy of a subject. Not asking for any secrets,, just some basic feedback. I could be wrong, but I don't think the 4/7 swap cams are legal in Stock.
Alan, I hope your custom grind works out for you,,,good luck with it. Danny Durham

There are many using the 4/7 swap cams.

Alan Roehrich · 04-26-2008, 07:58 PM

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 · 04-27-2008, 02:23 AM

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 · 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.

Geerhead55 · 04-28-2008, 08:28 PM

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

04-26-2008, 07:58 PM	#2
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,144 Likes: 1,623 Liked 1,954 Times in 440 Posts	Re: 396/375 camshaft questions 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. __________________ Alan Roehrich 212A G/S

04-27-2008, 02:23 AM	#3
Geerhead55 VIP Member Join Date: Sep 2002 Location: Tacoma, Washington Posts: 1,632 Likes: 0 Liked 5 Times in 5 Posts	Re: 396/375 camshaft questions 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

04-27-2008, 08:22 AM	#4
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,144 Likes: 1,623 Liked 1,954 Times in 440 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

04-28-2008, 08:28 PM	#5
Geerhead55 VIP Member Join Date: Sep 2002 Location: Tacoma, Washington Posts: 1,632 Likes: 0 Liked 5 Times in 5 Posts	Re: 396/375 camshaft questions 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