7.3 Heads on a 6.9

[BDCarrillo]

You got that right ^^. How many of those washers am I gonna need? Or should I put them on all my head studs?

I'd use them on every stud, you want that clamp load properly distributed. No need for a washer between the nut and insert.

 

[shocktrooper]

Any real quality difference? The TFS set is the same price as arp but for 20 instead of 10

 

[BDCarrillo]

Ehhh... TFS isn't up front on their material, while ARP is... TFS heads can push into the mid 350-400 hp range, but our IDI engines see a ton more pressure in the cylinder...

If it were me... It's a tough call, but I'd spring for the ARPs and not do any second guessing on their quality

 

[chris142]

Anything wrong with some grade 5 or 8 bolts from a hardware store???

 

[shocktrooper]

I'm actually using grade 8 bolts on the lower side of the head where they made the boss longer right at the manifold. It's just hard to get a 7/16 thread with a 1/2 shank. So I orders some of those washers that will take up the space.

 

[IDIoit]

I'm actually using grade 8 bolts on the lower side of the head where they made the boss longer right at the manifold. It's just hard to get a 7/16 thread with a 1/2 shank. So I orders some of those washers that will take up the space.

how long has this been running?

IMO, i would never use grade 8 on heads.
head bolts are hardened.

 

[shocktrooper]

Have not put them on just yet need to get dowel pins. I was thinking the same thing but at 85 ft lbs. I didn't know if I was gonna need stronger. The ones that came out where grade 8. But now that you have said that I might go a little higher.

 

[IDIoit]

grade 8 will stretch on you, guaranteed. thats what they are designed to do.
stainless will snap.
you need hardened bolts. dont stick just anything in there.
use the correct grade bolts.

 

[BDCarrillo]

I could go all structural engineer on this and calculate psi ratings for grade 8 and the awesome-sauce ARP uses, but it wouldn't be a fair comparison by a long shot!

Just please don't skimp on the head bolts/studs...

 

[Agnem]

It takes 18 hours to do head gaskets. If you would like to spend 36 hours because you used hardware store bolts, then by all means!

 

[OLDBULL8]

OEM factory head bolts are carburized and hardened, carburization is .030 to .035 depth at 1750*F and oil quenched to harden. IIRC.

 

[icanfixall]

Well said Brian & Mel. Grade 8 may work.. for a time but you will be redoing them later. This use of grade 8 bolts reminds me of installing ARP studs without removing the heads. Doing it one stud at a time. Scares the hell out of me but some have done it. My feelings are it can be done but how long it lasts is another thing. I know where and when it would fail on me. I'm just that lucky guy old on a black highway no moon nite and its late sunday when it lets go. Nobody can force you to do the right thing but if one has a hell bent pension to "do it" then please keep this forum informed on what happens. Thats how we all learn and change.
No I would never attempt grade 8 head bolts nor would I change to studs one bolt at a time in frame either.

 

[shocktrooper]

Yea I've been looking for longer 7/16 studs for those holes. Can't find any longer though. If you guys know where to find some let me know. Been on arp and everything nobody has longer than 6 inch. It requires a 7 for those 4 holes on each head.

 

[BDCarrillo]

http://www.summitracing.com/parts/arp-ap6-750-1sb/overview/

6.75" ARPs... I'd pop the head in place and take a depth measurement all the way down into the block to verify exactly how long you need, then call ARP.

 

[icanfixall]

Have not put them on just yet need to get dowel pins. I was thinking the same thing but at 85 ft lbs. I didn't know if I was gonna need stronger. The ones that came out where grade 8. But now that you have said that I might go a little higher.

Here ya go for dowels..
http://www.ebay.com/itm/251956146039?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT