JamesRich Posted July 14, 2016 Share Posted July 14, 2016 Hey guys, Can someone post a pic of their doug thorley headers, underneath from the back of the truck? I need to see how they clear the front drive shaft. Here's the problem I'm having. I cant seem to get a break on this truck with headers! James Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted July 14, 2016 Share Posted July 14, 2016 I have old pictures somewhere on my photo bucket Sent from my SAMSUNG-SM-N920A using Tapatalk Link to comment Share on other sites More sharing options...
JamesRich Posted July 15, 2016 Author Share Posted July 15, 2016 (edited) Link? I need to see how the doug thourleys clear the drive shaft. I couldn't have put them on wrong and they don't clear my front shaft. They are part number THY-464-2-C, from searching online they are the correct set for 4wd. Does no one else have doug thourley headers on their truck? James Edited July 15, 2016 by JamesRich Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted July 15, 2016 Share Posted July 15, 2016 Ahh can't help you... I think steevo can help before he threw an axle under his. Sent from my SAMSUNG-SM-N920A using Tapatalk Link to comment Share on other sites More sharing options...
JamesRich Posted July 16, 2016 Author Share Posted July 16, 2016 (edited) Yea that don't help! That just makes me want an SAS! Lol! Thanks for the pics though. I can see your Y pipe is shaped the same as mine, I guess that's my answer, Torch everything off the frame and put a solid axle! I sent Steevo a PM but he hasn't replied yet. How does the truck ride and drive with leafs in the front? James Edited July 16, 2016 by JamesRich Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted July 16, 2016 Share Posted July 16, 2016 It rides ok but needs adjustment once I get it rolling under its own power again. Sent from my SAMSUNG-SM-N920A using Tapatalk Link to comment Share on other sites More sharing options...
Precise1 Posted July 17, 2016 Share Posted July 17, 2016 I will take some pictures for you first thing in the morning Bud. I certainly don't have that problem, but I'll have to look again to refresh myself. What kind of front end mods are you running right now? B Link to comment Share on other sites More sharing options...
JamesRich Posted July 17, 2016 Author Share Posted July 17, 2016 Thanks B! The only mods to the front suspension are AC upper control arms, and sway a way torsion bars. I don't even have it cranked very high. These are the headers for the 90 to 95 and mines an 87 but I wouldn't think the axle placement changed. James Link to comment Share on other sites More sharing options...
Slartibartfast Posted July 18, 2016 Share Posted July 18, 2016 How are your front diff bushings? Long shot but that's all I can think of. Link to comment Share on other sites More sharing options...
hawairish Posted July 18, 2016 Share Posted July 18, 2016 These are the headers for the 90 to 95 and mines an 87 but I wouldn't think the axle placement changed. I see 3 different front driveshafts for an 87, apparently to account for configurations between the Z and VG engines, transmissions, and R180/R200 diffs. Perhaps the snout on one diff was longer than the other, effectively moving the driveshaft flange back a little? Link to comment Share on other sites More sharing options...
JamesRich Posted July 19, 2016 Author Share Posted July 19, 2016 My front differential bushings are still good, and centered. That's the first thing I checked. I understand different drive shafts, but even if the flange was further foreword The shaft would still be close to the pipe and would probably still hit during flexing. Now maybe the newer models have a higher pinion on the differential, that's why I asked for pictures of someones truck with headers that fit. Does Steeevo still visit this forum? I sent him a PM but he hasn't responded. I would say to hell with them and order a set of pace setters but they don't list any for 87s either. So far I've spent around $1500 trying to get decent exhaust on this truck and I still only have crap! Link to comment Share on other sites More sharing options...
hawairish Posted July 20, 2016 Share Posted July 20, 2016 Isn't the diff basically in a fixed position though? Even during flexing, the diff stays relatively stationary to the engine, trans, and t-case, minus small adjustments in mounts and bushings under torque. Both diffs were low-pinion, but if one snout was shorter than the other (a difference between R180 and R200?), the shorter snout would decrease the driveshaft angle and increase the gap, right? Sucks to have come this far, though. Hope you find a solution soon. Link to comment Share on other sites More sharing options...
JamesRich Posted July 20, 2016 Author Share Posted July 20, 2016 What I meant by flexing is the rubber bushings giving. That's the problem I had with the last Y pipe I had built for the set of headers I had from VG30.com. The pipe was on top the drive shaft and cleared while on the highway and going foreword in 4wd. When I put it in reverse the front axle pinion torqued up and started hitting the pipe. Since that was the second attempt at a Y pipe with the local shops I decided to not waste any more time and money on that set of headers because I had these DT headers sitting on the shelf since the group buy in 2012. I thought these headers would have solved all my exhaust problems, boy was I wrong! James Link to comment Share on other sites More sharing options...
hawairish Posted July 20, 2016 Share Posted July 20, 2016 I see, thanks for the explanation. I wouldn't have expected so much movement considering how the diff is mounted, but with worn bushings I can see that. But really it boils down to a manufacturing defect? I mean, how different is the cross-over point on these pipes vs. stock? Or is it same bends but with larger OD tube? Slight workaround, but could you use spacers and longer bolts on the snout's mounting points to increase the driveline angle enough to clear? Or are there offset bushings for the cross member by chance? Link to comment Share on other sites More sharing options...
Precise1 Posted July 21, 2016 Share Posted July 21, 2016 Sorry about the delay. Of course I forgot one day, got side tracked the next, etc. Typical, I'm afraid... Ok, so here are some pictures to show the relative spacing. I didn't measure the distance, but it is 1/2-3/4" by eyeball, if not more. I'm at somewhat of a loss as to why you would have such interference. Two thoughts are that my cross tube seems to be well behind the U joint carrier (look at the focal distance in the second picture), so does yours stand off from the front diff farther than later years, and are your Thorleys the original, or the second Gen were they made some minor changes? I'll be around tomorrow afternoon and will measure from the front diff to the beginning of the round section of the drive shaft, and maybe take a picture closer to our first angle for comparison. B Link to comment Share on other sites More sharing options...
JamesRich Posted July 21, 2016 Author Share Posted July 21, 2016 (edited) Hawairish, the bushings are still centered at rest, not sure how much they move under load or how much they are supposed to move. It's been so long I don't remember how the factory Y pipe ran. The last Y pipe I had on the VG30.com headers was just barely above the shaft. The exhaust guy probably didn't think the differential would have moved under load either. They were long tube headers and came really low and close to the shaft so they didn't leave much room for the pipe on a 4wd. They would make great 2wd headers though, they are very well built headers. I thought about spacing up the differential to clear but that will increase the CV angles a little. B, thanks for the pics. I see your headers are made just like mine and they clear. Looks like they are close to the shaft too but enough to clear. Can you get some pics of where the shaft crosses the pipe more from the side? James Whoa! I think I see my problem! After studying your pics B, I see your slip yoke is towards the transfer case, mine is at the axle. I removed the shaft once to pull the transmission but put it back the way it was. If the flanges are the same it can probably be put on either way. Somewhere before I owned it someone may have put it backwards. I will try to swap it around tonight. I'll be going crazy all day at work thinking about this! James Edited July 21, 2016 by JamesRich Link to comment Share on other sites More sharing options...
hawairish Posted July 21, 2016 Share Posted July 21, 2016 Whoa! I think I see my problem! After studying your pics B, I see your slip yoke is towards the transfer case, mine is at the axle. I removed the shaft once to pull the transmission but put it back the way it was. If the flanges are the same it can probably be put on either way. Ha! Hope that's it. I was just wondering the same thing when looking at the pics, before reading your comments. Link to comment Share on other sites More sharing options...
Precise1 Posted July 22, 2016 Share Posted July 22, 2016 Yep, that is it! You got yer drivin' shaft in bassackwards, boy! The front carrier has rounded corners where the tube joins the u joint carrier (fork?), the back are square; they appear to be equal length (forgot my rule). Front: Rear: B Link to comment Share on other sites More sharing options...
JamesRich Posted July 22, 2016 Author Share Posted July 22, 2016 Yea that was it! I don't have as much clearance as you but It doesn't hit now. There is quite a bit of flex in the bushing on that side but it still doesn't touch the pipe. If I still have problems with it hitting I will make a delrin bushing for that side and that will end the problem. Now that I got that problem done I can finish the job I started. I put a set of VG33 heads that I ported out and matched the ports to the intake. Y'all wouldn't believe how much the ports vary! Also put a set of reground Schneider cams (262 duration/.420 lift. I'll have to rejet my carburetor but needed to have the exhaust finished for a wide band sensor. Cant wait to see the difference all my work did. Thanks again B! James 1 Link to comment Share on other sites More sharing options...
Precise1 Posted July 22, 2016 Share Posted July 22, 2016 Glad to be of help, sorry for the delay. Yes, please keep is informed on how that worked out. That might be a nice mod for people who aren't ready for cylinder work, engine swap. B Link to comment Share on other sites More sharing options...
adamzan Posted July 22, 2016 Share Posted July 22, 2016 These pictures also demonstrate the clear difference in a wheeled, and non wheeled truck. 3 Link to comment Share on other sites More sharing options...
Precise1 Posted August 12, 2016 Share Posted August 12, 2016 Excuse me, NON DRIVEN truck is the case here. Not registered, in the driveway awaiting work... Feel free to post pictures of your own flogged, rusted, Canadian underbelly to offset things though! B Link to comment Share on other sites More sharing options...
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