After installing some longer overall length ARP 7/16-20 x .680" converter bolts I realized that the bolt head height is slightly taller than the recommended ARP bolt for this application. Big block w/Torqueflite. It reduces the amount of bolt head to block clearance by .040". It leaves me with an actual .059" clearance. Is this acceptable at this clearance as I need the longer overall length bolts ,as I am using ARP .120" washers to close the flexplate to converter gap back down to 3/16". Mopar length bolts become really short with a.120 spacer between converter and flexplate (B&M full round unit). There was an old post by Clanton where he used a similar bolt to get the extra length but there was no mention about trimming down the bolt head height for cleance issues. Anyone been here before? Thanks in advance. Bill

I wouldn't worry to much with .059 clearances to the block from the bolt heads as long as they are all that close or wider
I think the back of the block lower ears are closer than anything else between the block and torque converter, maybe not

I have ARP 7/16 thread torque converter bolts. I had to grind the heads down to get some clearance. I have .050" clearance between heads of bolts and block. I am using a Mazeire billet flex plate. I kept cracking the B&M, and Mopar performance SFI flex plates. Mazeire flex plate has been good for over a year.

If you decide to trim the head of the bolts down, just chuck each one up in a drill and put them against the bench grinder. Makes a nice pattern on the head, and trims them down quick and level.

When I had the washer I tried on both sides of the fp but ended up not using it because it gave a vibration even at idle.I did find my fp was bent .020 runout and got a new fp.

My true concern here is whether the .059" clearance between the bolt heads and the back of the block is sufficient. Everything is new . Converter, flexplate,and block. All straight and undamaged. Just wasn't sure about flexplate distortion at speed. Anyone had to check this measurement? Thanks, Bill

I don't believe there is any way for it to go forward into the engine with that much room.

Thanks for all the replies. It seemed like an ok number but just wanted to be sure that I didn't miss something important in the equation that I was leaving out.I appreciate all the info I get from y'all on this site. Thanks, Bill

I had two of the stock Mopar 7/16 converter bolts come loose and hit the back of the block knocking out some cast iron around the rear cam bearing boss and the two lower lips Not good
I use blue locktitte on them now torque to 55 Ft.Lbs

I run Turbo - Action 8 inch converters in my 904 both redone by Ultimate. I had a problem years ago with the " big " converter bolts being to long and bottoming out thus leaving a minuscule space between the bolt and the flex plate causing a flex plate cracking problem at the time. We shortened the bolts a little and it fixed the problem. I also use Loc Tite when installing the converter bolts also use it on the flex plate to crank bolts.

The flex plate in your picture - is that the B&M or Mazeiri.

What was the difference in thickness between the two?

The mopar fp is .100" thick so I would think all will be the same. just fyi.

Agreed. Was wondering why the statement “billet” was used.

Likely just another stamping.

The Mazeire flex plate is suppose to be a billet piece. It is .100" thicker. The flex plate in picture is of the Mazeire flex plate. It was taken with my phone. Don't know why it turned sideways when pic was posted. Pic also lost clarity. Mazeire flex plate has a lot more material from the flex plate bolt hole to the outer edge. That is where the Mopar Performance and B&M flex plates use to crack.

I have 6 or 7 cracked flex plates on a shelf in my shop.

The Maziere flex plate cost $550 . But it works.... no cracking.

That is one hell of a piece of bar they machine from.

I think I would, and you should, find out why that motor is cracking the flex plates
I've seen one stock 904 flex plate break all four fingers, main things going out to the converter bolt holes, and one of the original street hemi flex plates crack around one bolt from the hole to the outside edge of that flex plate

Mine all cracked at the outer bolt holes. The B&M flex plates have about 1/8" from outer bolt holes to edge of flex plate. The mopar performance flex plates have about 1/4" from outer bolt holes to the edge of flex plate. All of my cracked flex plates cracked from that outer bolt hole to the edge. The Mezeire flex plate has a little over 1/2" from outer bolt holes to edge of flex plate.

I have 3 different torque converters since 2004. All cracked flex plates have been since 2004 up to 2020. No cracked flex plates since going to Mezeire flex plates. Also had 3 different stock blocks, and a Bill Mitchell block for the last 6 years.

Pic of last broken B&M flexplate, from last year.