Flywheel Bolts Questions

KaLiKo Street

Member
Feb 2, 2012
73
0
6
Im doing a 5.0 swap with my 92 2.3 and got ready to sit the motor in yesterday and noticed I didnt have the right size flywheel bolts. I had the ones from the 2.3 which are the right length i believe but are not thick enough to fit snug in the back of the crank so i called advance auto and they said non of there stores or warehouses carry flywheel bolts and they cant order any either. So i got NAPA and they order some that they say will fit the 5.0 302. So i get them to order them and pick them up today and there TINY...There about half the length of the 2.3s bolts...there the right thickness though, and the heads a different shape/size. Im worried that they wont be long enough or may strip the threaded crank holes if they were to see a small amount of power from the motor and just rip them right out...get what im saying? What you guys think? Think they will be alright? I'm guessing that some ones has to of had run these before on something...they are for a 302 so. I dont really have any other choice other then going to a junk yard and pulling a motor out just to get the flywheel bolts...

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The one on the left? The one on the right came from my 2.3...
i dont think there long enough to hold in

I got some of these which are exactly the right size and thickness and everything but im worried that they may not be hard enough. There grade 8 bolts though...

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Ima just try to grade 8 bolts. No one around here has what i need an i dont feel comfortable with the little one so...I dont see what it matters what exact bolt you use. The grade 8 bolts will stand up and hold i believe...the real flywheel bolts are only grade 10 so i dont see much difference
 
I went with the ace hardware store bought grade 8 bolts with loc-tite on them and torqued them to 80 ft lbs. There grade 8 (10.5 in metric) 7/16 bolts, 150,000 psi made of Med. Carbon Alloy Steel. I believe the orig. flywheel bolt is around a grade 8 or 9? They have the same 6 hash mark lines on the top as the ace ones do...Theres 6 of these things and there pretty thick, are longer then the small flywheel bolt on the left and have loc-tite on them, is a stock 5.0 with a t5 capable of breaking them? Im not trying to loose my legs or anything if this flywheel where to come off.
 
IIRC, the thin heads are there so they don't have any interference with the clutch disc. I can't really tell how thick the heads are on those bolts you bought, but I know the ARPs I bought several years ago for my car weren't much thicker-if any-than the ones you bought from NAPA. That being said, I'm inclined to agree with ID89GT-they might've ordered bolts for a flexplate.

Just a recommendation: may want to check for interference between those bolts and your clutch disc....
 
The grade 8 bolts i put in are the exact same length and size as the 2.3s flywheel bolts and the automatic 5.0 bolts. I believe the only difference with the real flywheel bolts and what i have are that mine arent corrosion resistance and real flywheel bolts are...but the motor will prob be rebuilt again long before the bolts corrode.

And the ones i put in are the exact same grade that we all depend on to keep our wheels on our cars. You can hit a pot hole at 150+ mph and your wheels dont fall off right? Grade 8 studs is what keeps our wheels on with only 4 or 5 bolts so im hoping that 6 with loc tite will hold a flywheel.