The 1x4 and 2x4 are not the same. The nipple locations are different. If you're not using a Turkey pan, than you could use the 2x4 log. But if you are using a pan, you need the proper 1x4 log if you want the fuel lines to line up with the inlet holes in the pan.
Here's an original 1x4 log on my motor...
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Sal Mennella
CSX 4241, KMP 357 - sold and missed, CSX 4819 - cancelled, FFR 5132 - sold
See my car at CSXinfo.net here >> CSX 4241