MustangChuck 16 Report post Posted May 16, 2012 I seem to have lost my originals. Can anyone please tell me the thread size and length of the bolts that go into these holes? I assume that #1 and #2 are the same thread size and #3 and #4 are probably the same size and length. This is the firewall where the master cylinder mounts. My car was originally a manual drum (6 cylinder) car. Any help would be greatly appreciated! Thanks! Chuck Quote Share this post Link to post Share on other sites
Mike65 476 Report post Posted May 16, 2012 Chuck, My 69 Coupe is a manual drum car but a 302 originally. All 4 bolts are a 9/16" head, & the 2 top bolts which I can break free & remove look like they are 3/8" threads. I cant get a good bite on the master cylinder bolts to get one out to measure as I have stuff along that side of the car in my 1 car garage. Hope that helps you out a little. Quote Share this post Link to post Share on other sites
MustangChuck 16 Report post Posted May 16, 2012 Thanks! I did a lot more digging. Finding the exact thread size and pitch has been frustrating. I believe the master cylinder bolts are (if the eBay auction was correct) 3/8"-16 and are 1.5" long. If the top two are also 3/8", they are probably 16 pitch threads (coarse?). Length unknown. I am planning to stop by Lowe's on the way home and grab a packet of 3/8"-16 bolts. I'll post my findings tomorrow. Many thanks again, Mike!!! Chuck Quote Share this post Link to post Share on other sites
Mike65 476 Report post Posted May 16, 2012 Thanks! I did a lot more digging. Finding the exact thread size and pitch has been frustrating. I believe the master cylinder bolts are (if the eBay auction was correct) 3/8"-16 and are 1.5" long. If the top two are also 3/8", they are probably 16 pitch threads (coarse?). Length unknown. I am planning to stop by Lowe's on the way home and grab a packet of 3/8"-16 bolts. I'll post my findings tomorrow. Many thanks again, Mike!!! Chuck You are welcome, thats why we all come here to help each other out when needed. It just happens my car is torn apart so it was no big deal & I am glad I could help someone out when needed. Mike. Quote Share this post Link to post Share on other sites
MustangChuck 16 Report post Posted May 16, 2012 I really appreciate it! Chuck Quote Share this post Link to post Share on other sites
SELLERSRODSHOP 13 Report post Posted May 16, 2012 i've got mine out & laying on the floor, give me a few mins & i'll get a measurement.... Quote Share this post Link to post Share on other sites
SELLERSRODSHOP 13 Report post Posted May 16, 2012 the two that hold the master cylinder are 3/8x16 & 2" long. Quote Share this post Link to post Share on other sites
MustangChuck 16 Report post Posted May 17, 2012 Thanks, SellersRodShop! I confirmed yesterday that the upper two bolts (#1 and #2) are also 3/8"-16. I don't know how long they were originally. Thanks again to both of you! I really appreciate it! Chuck Quote Share this post Link to post Share on other sites
SELLERSRODSHOP 13 Report post Posted May 17, 2012 i'll get a measurement off a top one in a few... Quote Share this post Link to post Share on other sites
MustangChuck 16 Report post Posted May 17, 2012 SellersRodShop, if you also have access to your master cylinder, would you please measure the length from the flat mating surface to the tip of the pedal rod? Located with my lost bolts is my master cylinder (I hope). I am getting measurements to begin my hydroboost install. Many thanks! Chuck Quote Share this post Link to post Share on other sites
SELLERSRODSHOP 13 Report post Posted May 17, 2012 pedal rod is 4.5" from the master rear flange to center of the hole where it attaches to the pedal... here are the bolts. short ones are 1 1/4" long, master cyl bolts 2" long. Quote Share this post Link to post Share on other sites
MustangChuck 16 Report post Posted May 17, 2012 Very awesome! Thank you so much!!! I greatly appreciate it! Chuck Quote Share this post Link to post Share on other sites
SELLERSRODSHOP 13 Report post Posted May 17, 2012 no problem! let me know if you need anything else. Quote Share this post Link to post Share on other sites
