"Midnight Rider" 1970 C10 SWB Fleetside

[Shifty One]

"Science bi*&hes"!

[omodified]

Been gathering ideas for the exhaust. Due to my motor being rated at 550hp, I decided a few months ago that 3 inch exhaust was in order. You may have seen in an earlier post where I polished out 3 inch inlet/outlet mufflers. Well, the struggle I reached recently was that the headers I currently have installed are 2.5 inch at the collector. It's too bad because I really like the look of these and the clearance they offer. I looked into using a 2.5" to 3" adapter, but I also read where 550hp+ engines should have 1.75" primary tubes or bigger. These shorties are 1.625" so it's time to find something different.




I tried to find a manufacturer that makes a set of shorty headers that meet my specs. Unfortunately, there isn't anything out there with a 3" collector. So, I started looking at long tubes. A few members on this board have used Doug's D3348 headers with pretty good results. So, I decided to start there. I went with the model specifically for 67-72. I like the idea that these are already coated. I was going to have to coat my old short headers anyways, but I wont have to worry about that with these. I got the right side installed, and the clearance was very tight to the frame rail, 0.005" at the closest point. I need at least 0.375" to feel comfortable. I didn't really want to remove this much material from the frame and I also didn't want to dent the headers. So, I decided to send these back. I wasn't very happy with the welds on these anyway.


















Since I really liked the TIG welds that the Speed Engineering short headers have (way nicer than Doug's partial MIG welds) I decided to try a set of their 25-1066 mid length headers. They don't offer anything specific for 67-72 C10, so I went with universals. They are for LS engines so I assumed the fit would be close. Well, I was wrong. They look really nice, but the collectors are aimed toward the transmission. In fact, they hit where I have already removed the transmission ears. I can't take anymore material away from there, so these will get sent back too.






Next, I decided on a pair of Speed Engineering 25-1025 long tube headers. These have a ton of clearance to the frame on the driver side. They do hit the corner of the block ever so slightly. I will need to clearance the block there about 0.00625".










The passenger side is a little closer. I have 0.080" of clearance to the frame. Better than Doug's but I will still have to remove some of the frame to get enough clearance. I really do like the looks of these headers, so I think I will keep and use them. I used a large metal file to attack the frame. Using a grinder might blister the paint on the frame and make it harder to touch up later. After filing for what seemed like a day, I ended up with 0.400" clearance and some damn good looking headers.