From reading you post title I was going to say no. But now I see how cheap you are gettin them, and I say definatly go for it. Therse only a few % difference that is about 300rpm on the freeway in 5h gear. So I wouldn't worry about it. I think you'll hit 12's no problem.
Skyler
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-1989 Saleen Mustang #406- TFS Heads, E-303, edelbrock intake,70MM TB, 73mm MAF, off road H, headers and 3chamber flows.
12.55@107mph
Runs on 87 Octane and gets 24mpg!