I must say to start, my service manual doesn't mention anything anywhere about not reusing IM bolts or any other that I've come across..With that said TTY bolts are: Bolts that are torqued to spec..But some bolts that are torqued to spec such as IM or plenum pan bolts that are torqued in a three step sequence 'should not' be reused..When torqued to spec in a single step it's referred to as 'Elastic deformation' and when torqued in a multi step sequence it's referred to as 'Plastic deformation'..the 2nd type is when the bolt has changed shape and or length..As a result they 'should' not be reused...

 

 

The 3 step torque process on the intake mainifold is to get it to seal to the heads properly.

 

Yup, just like using the star pattern when tightening lug nuts! Seat it evenly eh...

 

Yeah, its been an ongoing debate whether the intake bolts are TTY, re-useable or what.... for my part... when I had them off, they were cheap, low grade bolts, of which, two broke off when pulling the intake. I replaced them. While it may not be absolutely necessary...... it strikes me as 'just a good idea', given the (lack of) quality of the bolts. Replacing them with some good grade 5 fasteners, or better..... would more than likely solve the issue permanently.

 

I've used SS button tops from day one with a little anti sieze, used them with 3 different manifolds on 4 different heads...Never had a problem.

But yeah, the stock bolts are junk....And how can anything be TTY with 12 ft lbs of torque anyway?

 

And valve covers, diff covers, plenum plates and cylinder heads etc etc...Start from the center and work your way out, rinse repeat.

 

True, true..not to mention a new set came with my hughes kit Silly Q, what's better grade 5 or 8?

 

Grade 5 will expand, bend, and contract with the motors heat. Grade 8 are more brittle but stronger. When they break they just snap not bend. Use the right bolts for the right job!

 

Wonder why that's what the dealership sells & why hughes sent me grade 8's then..I got duped man!