[TR] TR4A Piston Upgrade

[Pat Caffrey]

Hello, 

I'm having an engine rebuild on my 1967 TR4A and am considering upgrading the pistons to either 87mm or 89mm. The car is strictly for street driving. I'd like to get more power out of the engine but fear 89mm may be too much. Still, 89mm is only 3mm bigger than the stock 86mm pistons. Any thoughts on which direction I should go? 87mm or 89mm? 

Thank you, 

Pat