a double roller timing chain wont give you more power than a gear drive
the only reason i would replace it with a roller chain is if you hated the noise of a gear drive
ok,,, more power for cheap.... good set of headers and dual 2.5" exhaust with a good hi performance muffler open element air cleaner edelbrock performer intake
you probaly already have a HEI maybe get a hi heat coil good set of MSD 8mm wires and oh yea a good sized cam,,,
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