340 HP balncer

[super sport]

will someone post a picture of a 340 HP balancer for a 409 and what is the width of it 6 inch or 6 3/4 inch ?

[rod61727]

I am re-doing a 340 hp...couldn't find the right size either...Finally did find out the size required...6 3/4 is too big to clear the timing tab on a 340 hp (409hp and 425 hp use a 7" balancer, and the tab is farther out on these)...some people will say to move the timing tab out and use a 6 3/4 or even 7" if you have one...I'll have to check to be sure, but I think the correct dia is about 6 3/16...some guys told me 6" will work fine, but a friend with the correct one gave me casting # and dimensions...I can dig out the info if you want it....ANYWAY, what I ended up doing is buying a 6 3/4 balancer, and had a machinist turn it down to the correct dia, and relocate the timing mark to 12 o'clock as it should be for a 409 (this suggestion came after one of the major parts suppliers for 409's told me that's what they do to provide "correct" balancers for 340 hp). This balancer is also the correct thickness and configuration for the pulleys. I think I had an extra one turned at that time...I'm pretty sure I blast cleaned and painted it with the one I put on the engine...If you need it, I'd sell it for $45 plus shipping...I think I also bought a 6" somewhere along the way, but didn't use it...anyway, let me know if any of this will help you...

[super sport]

i also have a 6 3/4 balancer that i purchased on e-bay and it to did not fit my timing cover , it looks very similar to my 425 hp 7 inch balancer . that why i was wanting someone to post a picture with a 340 balancer. thanks for the info .

[models916]

Use the timing tab from Show Cars, it clears the larger SBC damper and corrects the 10 degree tdc move. Just cut the old one off and grind the cover smooth. New tab bolts to the timing cover with two bolts. Looks like a later GM style tab.

[CDNpontiac409guy]

I took a few pictures today.
Here are photos of an original 1964 409 340 HP balancer.

Is 6.25" inches diameter.... 1.25" thick.

[super sport]

thanks for the pictures and info Aubrey , model 916, and rod61727 ,, i now know i have the wrong balancer .. :bang