Final state of truck restoration. Want to move on completing the exhaust sys. for my truck and couple issues have come up that i thought would post and see if any members can offer suggestions, or opinions.

Just installed headers in 65 w/ 302. It is 3 1/2" at the collectors. Need to purchase remaining portion of the exhaust sys. Considering reducing to 3" and running 40's, but if memory serves me, there is an article indicating that you want to maintain some back pressure for better performance. If recall, it was a high tech article and i kind of glossed over it. Wonder if i should consider going to the 2 1/2" to obtain better performance for the 302.

A do it myselfer and was hoping i could install without towing to muffler shop. Quite a distance to local muffler shop and wanted to save some money. Looks like in order to route the exhaust over the transmission crossmember i will need to weld a short offset aft of the reducer. Have oxy-acel with limited welding skills but should be able to weld section of pipe. Seems like this would be a common jointer for truck application and if anyone has found a reducer for this application. Holding off purhasing because if it requires above adverage skill would it be best to have muffler shop purchase and install the system.

any suggestions would be appreciated.


thank you,
dave

 

How many mods have been done to the 302? I have talked with a shop here a few times, the owner races stock cars. He says that a 302 should be good with 2.25" or 2.5" and supposedly 2.25" will flow good enough for a 460 with the right mufflers. I am not so sure about that but 3" might be a bit big for such a small motor, 2.5" might even be a bit big.

 

Thank you 351M. Probably go with the 2.5". Was considering going smaller in order to keep the stock mufflers recently purchased. Cheap one's so no great loss. They are 2" and think it would be too small. May have another option, received an email couple hours ago from person i purchased the headers from. He is interested in selling the entire dual exhaust sys. that came with the headers. Came off 67 truck so everything should hook right up. It includes the two mufflers, and the set up is about 2 yrs. old. Probably can get everything for around $110 which would include shipping. Anyhow, intend to email and inquire about pipe size and give some consideration.

thanks again for the info,
dave

 

That sounds like the cheapest wnat easiest way to get a good system, Hope it works out for ya.

 

Forget what you read about backpressure, its bad. You dont want any.

 

Don't mean to start a boxer vs briefs contravercy but came across the article on "header basics" by Loren Barnes. There are probably a number of conflicting articles on the subject. Seemed bit too high tech for me, but still of some interest. Was able to locate the article by typing in the internet search field " s and s headers" (as typed) and opening up the web page for s and s header manufacturer ' header basic A guide'. Anyhow, for anyone who is interested, may want to browse the article.

dave