v8 engine crossmember bolt size & threads

I am trying to find out what size bolt to use and what thread pitch etc. to use to install the v8 crossmember in my 1970 Maverick.

 

If you are using a stock Maverick crossmember it takes a special bolt with a beveled head. Not saying that you cant use something else, sorry I dont have the information about size and pitch. Many distributors sell them but I posted a link to the page in Melvins Maverick catalog

https://www.parts123.com/parts123/dyndetail.pta?acclink=0001018oAABIF

 

Ok thanks

 

1/2"-13 x 1-1/8" long special hex-head countersunk bolts

 

thank you

 

https://www.ebay.com/itm/1964-1970-Ford-Mustang-Frame-Crossmember-Bolts/392148899399 best price on them.

 

thanks

 

For amount of actual contact those countersunk bolts have on the bar, no doubt a regular grade 8 washer and std bolt would give more rigidity.

 

why was the bolt designed like that?

 

I dunno. My guess is for amount of flex in the stock configuration, countersunk bolt is good enough.

Ease of install on assembly line also probably a factor.

 

makes sense about ease of installment on assembly line, don't really have to worry about over tightening with the countersunk bolt

 

Counter sunk bolt will not allow the bar to move around under the bolt head where it could with a regular bolt and washer. I do agree though, for what it is and does a regular grade 8 bolt would be more than adequate.

 

Isn't one end slotted vs having round opening?

 

Well I think I have to run a chaser through the threads because I just tried to install a 1/2" x 13 x 1 1/2" hex bolt in the hole and it only went in a couple of threads, mind you I am laying on the ground and reaching under the car since I don't have it up on jack-stands yet, all in due time...

 

Good question, it's been so long since I looked at mine I don't remember. It would make sense that it was considering the precision these cars were assembled with. I guess I'll have to see if I can find it!