What Do I Need To Stroke A 351 Cleveland To A 393 Or A 408ci??

HI, I am trying to build a 393 - 408 cleveland stroker. I have forged diamond flat top pistons with a compression height of 2.265 and .030 bore. Have crank ground to take chev rods. Can you help me on the length of the H-beam rods needed. Would this be 6.0" Or 6.2" useing 4V close chambered heads and a Inlet valve lift of .578" exaust of .590" and an average duration of .315 degres.


Hope this is not over the top, any help would be appreciated.


Cheers Brad
What Do I Need To Stroke A 351 Cleveland To A 393 Or A 408ci??
with your combination you would go with the 6.0 rods. if you go with the 6.2's your piston will be sticking out of the block. literally.


what journal do you have the crank ground down to? im guessing the normal 2.000 chevy rod journal size. also, make sure (if you havent already) gotten valve reliefs cut into the pistons because with that high lift of a cam you will definitely be touching piston.


another thing that comes into play with this is your rocker arm ratio. the bigger the ratio ie: 1.6:1 vs 1.7:1 the more valve lift. but you probably already know that.





personally, i wouldve went with a 351W stroked to a 427. its a great combination plus parts are cheaper and you can get ALOT of horsepower out of it due to its larger nature plus because of its immense stroke, your torque would be unbelieveable. but anyway, good luck with your project!


Just make sure those valves dont touch piston! mock it all up and put some clay on the pistons, put on the heads and run it through 1 turn. if it stops or there are indentions in the clay, your gonna have to cut deeper valve reliefs into the pistons.