Early Ford 289 valves (look up 1965) are just the right size for a size-up valve replacement, and Star Performance is selling Elgin
I-1670B (1.780") &
E-1669B (1.453") valves for
$3.70 &
$3.62 per-pair. Google those part numbers - this is a deal!
The suffix "B" in the part number indicates a boxed-set of two - be certain to order using these numbers. The length is comparable; but may require slight massaging to work. My full set cost $32, with shipping.
Not sure how long this pricing will last... mine are due to arrive Thursday :)