302 pistons using 289 length rods

[Kev Farrington]

I want pistons to suit my engine but not sure where to get them. I`m using standard stroke 302 with 289 length rods ( Boss302 crank and rods ) that I`ve had for years and want to use. I will be using Victor Junior type heads so flat top pistons are what I need I think? Does anyone know where I`m likely to find any? Thank you for any help you can give and apologies if it has been covered before.

 

[colin artus]

For that combination you need a piston with a comp height of 1.55" which is not an off the shelf height and if you must use those rods then a custom piston will be your solution (JE,Ross,Wiseco et al). This will also allow you to run the cr that you want. A cheaper solution would be to ditch the boss rods and use an aftermarket rod of 5.4 inches and a piston with a comp height of 1.3" of which there is a wide choice as this is a popular 'long rod' combo

 

[Jac Mac]

Do some measurements of the block etc before buying stuff, Early blocks usually have a bit more deck height than the 'published' 8.210" which means you can use std 302 pistons with about 0.025'' or so off the top and a fly cut of the valve pockets. Keep any deck machine work to a minimum to simply 'square the block'. Ive done a lot of this particular build, and if the 289 crank was worn it was less expensive to buy a new 302 crank and rebuild the engine as above.With Scat & Eagle now having steel 302 cranks its an even better deal.

 

[Kevin Box]

Kev

Agree with JacMac
Maybe look around for some new old stock forged pistons as they have a thicker crown.

Failing that the 5.4 is a good option

I've done the 400 Chev rod combo (5.565") before with KB276 pistons and that works nice but a bit of a journey.
2.1" big end size and narrowed rods with Chev V6 bearings.

cheers KevinB