Should I get the extra 8 bolts and make it 18, or is 10 good enough?

I done sum searching and was reading that lots of guys are running lots of boost with 10 bolts and no issues and others say go with the 18, so I still havnt got a clear answer.
Motor is a 600ci with c460 heads, a460 block, 15:1 cr. it's mostly n/a but will see a 300hp of nitrous about 20 times a year.
The motor currently has 10 head studs per head, so I was wondering should I get the extra 8 to make it 18?
Thanks

If you have the correct heads and block use them. Just remember you need to get the correct head gaskets too.

There are early a460 blocks and C heads that are only 10 bolt.

If its an 18 bolt block, why wouldn't you?

Yes the block has the provisions for 18 bolts

rocketpony wrote:Yes the block has the provisions for 18 bolts

Be aware that Ford had two distinctly different 18 head bolt patterns.
One uses the normal 10 bolts with 8 more added and the other uses all 7/16" bolts in slightly different locations.

rmcomprandy wrote:

rocketpony wrote:Yes the block has the provisions for 18 bolts

Be aware that Ford had two distinctly different 18 head bolt patterns.
One uses the normal 10 bolts with 8 more added and the other uses all 7/16" bolts in slightly different locations.

Are you referring to the A500 / E460 pattern pro stock stuff?

I'm not aware of multiple 18 bolt stuff on a460 blocks and C460 heads.

TFS sells a kit that has the additional 7/16" fastners.

The 10 are 9/16 head studs, with an additional 8 holes that are 7/16

dfree383 wrote:

rmcomprandy wrote:

rocketpony wrote:Yes the block has the provisions for 18 bolts

Be aware that Ford had two distinctly different 18 head bolt patterns.
One uses the normal 10 bolts with 8 more added and the other uses all 7/16" bolts in slightly different locations.

Are you referring to the A500 / E460 pattern pro stock stuff?

I'm not aware of multiple 18 bolt stuff on a460 blocks and C460 heads.

You may not be aware of a lot of stuff; there is that "Pro Stock" 18 head bolt pattern that came standard on D460 heads which ARE the C460 head castings; (so they initially look exactly the same).
I have personally used quite a few, years ago.

rocketpony wrote:The 10 are 9/16 head studs, with an additional 8 holes that are 7/16

That bolt pattern you mention certainly are the A460 block. Just be sure the heads match.

Can you just add the bolt to an existing combo, or will the additional bolts impact cylinder roundness requiring re-hone with appropriate plate?

Calypso wrote:Can you just add the bolt to an existing combo, or will the additional bolts impact cylinder roundness requiring re-hone with appropriate plate?

Answer your own question.
Why would you wish to use a stress plate on the deck when honing, in the first place...?
Adding the clamping load of more fasteners changes the stresses.

This motor was always ran with just the 10 head studs, so would anything need to b done if I wanted to run the extra 8?

[quote="rocketpony"]This motor was always ran with just the 10  head studs, so would anything need to b done if I wanted to run the extra 8? [/quot]

looks like you missed to post above post by Randy M.

I seen the post by randy , but I don't understand if anything or what has to be done when adding the additional 8 bolts

Given the distance from the bore and the lower tq. value of the small 7/16" hardware, I do not perceive any critical issues in adding the eight extra fasteners .

 

Thanks for the help again.
So tfs makes a kit with the extra 8 bolts right? Does arp also? Is there one I should go with?

rocketpony wrote:Thanks for the help again.
So tfs makes a kit with the extra 8 bolts right? Does arp also? Is there one I should go with?

No, I said 'TFS sells' the kit. ARP make the stuff in the kit & TFS sells it.....as far as I know ARP does not offer the fasteners as a kit.

Perfect thanks again