According to the specs for the TRW-L2446f pumps, they are for 9.503 deck height blocks. The '69 is 9.482 or something like that. You MIGHT be able to put a GOOD head gasket on and get by, (not all would work!) Being your first build, you should check into swapping out the TRW's for something else or playing with the rod length as Harris is implying....good luck!
greg
Specifications:
* Bore: 4.00 in.
* Stroke: 3.50 in.
* Rod length: 5.956 in.
* Compression ratio: 9.19:1 (60.4cc heads), 8.95:1 (63cc heads), 8.46:1 (69cc heads)
* Head type: .110 in. dish
* Oversize: Standard
* Ring size: 5/64 in. top/second ring, 3/16 in.
oil control ring
* Weight: 639 grams
* Pressed pin only
* 351W block with 9.503 in. deck height