How hot can aluminum heads get before they warp?

[jimberg]

I remembered reading something about old 351 blocks and water passages. This was a blurb in the installation notes for my TFS TW heads.

Quoted from Trick Flow Twisted Wedge Installation Notes:
Note that the large coolant holes always go toward the rear of the block. If you have a pre-1972 block or a 351 SVO block, you must modify the coolant passages in the deck surface as shown in Figure 3. Using the head gasket as a template, drill into the water jacket at the locations shown with a 3/16 in. drill bit. This modification must be done to prevent overheating due to steam pockets forming in the high side of the block. Be sure to tape off or otherwise cover the deck surface and cylinder bores when you are drilling.

Did you do this?

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351W 89 Mustang GT Convertible

[This message has been edited by jimberg (edited 07-31-2001).]