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73-87 Chevy _ GMC Trucks => Performance => Topic started by: Ronno6 on November 04, 2018, 06:11:37 PM

Title: Bolting on Aluminum Heads
Post by: Ronno6 on November 04, 2018, 06:11:37 PM
What sort of strange and exotic things do I need to learn in order to bolt on a pair of small block heads?
Any certain way I need to hold my mouth when I torque them??
Title: Re: Bolting on Aluminum Heads
Post by: bd on November 04, 2018, 11:04:21 PM
Guide to Thread Sealing (http://forum.73-87chevytrucks.com/smforum/index.php?topic=35601.msg300976#msg300976) - scroll downward.
Title: Re: Bolting on Aluminum Heads
Post by: Ronno6 on November 05, 2018, 08:34:24 AM
Excellent read. Thanks.
Should I be using washers under the head bolts?
Title: Re: Bolting on Aluminum Heads
Post by: bd on November 05, 2018, 08:56:33 AM
Absolutely!  In addition, I recommend flipping for a new set of ARP head bolts, which come with matched flat washers.  The ARP washers have chamfered IDs that face the head bolt flanges.  The chamfer provides needed clearance with the under head radius of the flange to dismiss stress risers in the bolt.
Title: Re: Bolting on Aluminum Heads
Post by: 75gmck25 on November 07, 2018, 07:15:34 AM
I used a new set of ARP bolts with my aluminum heads, and so far its been working very well.  You just need to have an accurate torque wrench, and follow the graduated sequence to torque them down (I think it was in three steps, gradually getting tighter each round). I also chased on the threads first with a tap, and made sure the bolts threaded in easily.  The ARP set came with assembly lube.

I replaced old stock heads with 64cc aluminum, and I used thinner head gaskets to get a little more compression. Stock gaskets are .039" thick, and there are several brands available.  However, I used Mahle .026" thick gaskets (https://www.summitracing.com/parts/cle-5746), which should bring compression up about .2 points over the thicker gaskets. 

Bruce