pushrods

[mark r. brown]

i have a 67 300 that i wish to convert from a 2bbl to a 4bbl setup. i bought an aluminum intake from a 64 300 and also the matching aluminum heads which i have at a local machine shop to be rebuilt. one of the heads is warped so i'm planning to have both milled down so they match. my question is this, do i need to get different pushrods or not? i had one guy tell me i do but i remember reading on this site some time ago to just swap the aluminum heads with the cast ones and you're good to go. any help or info would be appreciated, thanks rooster.

 

[DB]

As long as you are not putting in a higher than stock lift cam, you should be fine.

 

[gmranch]

Your 64 300 aluminum heads have smaller valves than the 67 300 cast iron heads. Have the Shop machine the existing valve seats in the 64 heads to accept the larger valves from the 67 heads. Do not attempt to install larger valve seats as there is not enough material on the 64 heads to do this(you will break into the water jacket or out of the combustion chamber!). I am currently doing this on a set of 64 aluminum heads.