Unbelievably Tight SBC Freeze Plug Installation

[Bohemian]

I've r&r'd a lot of freeze plugs in & out of the vehicle a lot of them sbc's.

I'm currently using a Snap-on 2009FPIKit, Freeze Plug Installer tool.

I'm trying to install new brass, made in usa melling freeze plugs in a new Dart 434CI SHP SBC Block on a engine stand.

These are by far the hardest freeze plug install I've ever had to do, there's a crazy amount of press required on these 1-5/8" freeze plugs I'm calipering em at 1.635"-1.640" and the block holes are calipering at 1.610". I don't have another block gm sbc or other wise to compare them to, but I'm thinking that's on the tight side, but maybe for a reason unknown to me.

Freezing the plugs first and heating up the block does not help and i'd need an walk in oven to heat up the whole block.

I have some dart brand freeze plugs & some other no name freeze plugs and they all seem to be in the same 1.635"-1.640" range, so I'm scratching my head on this one.

Anybody use a different tool than the snap-on one I listed for tight freeze plugs? i've used sockets before but that's less than ideal and the snap-on tool is purpose built. This is the first time I've had any trouble with it or installing new freeze plugs on a engine stand where I have all the room in the world.

Also if anybody has had any simlar experience installing tight ass freeze plugs in a Dart SHP SBC Block or otherwise I'd be interested in how you overcame this challenge.

thanks in advance.

 

[Wes Harden]

Yeah have that tool works good. I'm going to measure a sbc freeze plug opening. Let you know what get

 

[Wes Harden]

I measured .628 77 sbc 400 block

 

[Fordum]

Maybe some rust or corrosion in the block? Or, if they have been replaced before, the PO might have used some glue or other sealer and there is some left in the hole.
If the block is out of the truck, maybe some Scotch-Brite wrapped around a drill to polish the holes.

 

[Bohemian]

brand new Dart SHP SBC Block, on a engine stand, new 1st time install.

 

[Fordum]

Well, theres your problem..........................................
Its a virgin!!
Be gentle......

 

[Bohemian]

My Solution... different tool

Snap-on Store

shop.snapon.com

The 1-1/2" x 1-5/8" adapter fits the sbc freeze plugs tighter and putting the driver nut on the driver handle before the adapter like you would normally use it (threaded end of driver handle too long otherwise) worked out better than my other snap-on freeze plug tool, I think it was a combination of the dart block freeze plug holes being smaller than other sbc blocks and my ball end offset freeze plug driver set & adapters fitting looser in the freeze plugs. too many things to try and keep straight & lined up with install of really tight freeze plugs while swinging a hammer big enough to get the job done. The dart block also has more metal around the freeze plug areas than gm sbc blocks do, so whatever you use to put the freeze plugs in with needs to be pretty close to the same size as the freeze plug itself.

there's a bunch of these sets on ebay in various condition right now if you don't want to buy a new set and think you might have a use for a set like this.