I think is 1.6 but I need to know for sure.


Thanks.

 

yes, it is 1.6

 

1.6 is the stock ratio, and don't get sucked in by those who use 1.7's. The fact is 1.7s on a sm block really don't give you any extra horse power or tourqe (5 if your lucky) and they where down your valve guides faster due the increased stress. You should only get extra lift from your cam. (My info can be backed up by the August 04 isssue of 5.0 mag)

 

agreed, it throws off the valve train geometry

 

Do you know if that article is available online? I'm not disagreeing with you or the article, just trying to understand, but I can't see where a larger ratio would cause increased wear on the valve guide or stem since the geo change is at the rocker arm end. The distance from center line of the stud/bolt to the center line of the valve stays the same.

 

I read about it years ago in one of the rags, but I think it placed the rocker arm contact slightly off center and at an angle to the valve stem - that put slight lateral pressure on the valve and ultimately the guides. The article was pretty techy but it sounded convincing. Honestly I ran 1.7's in all but one of my 5.0s and never had any problems (30K miles at the most).. Once I read the article I stopped using them and just used the cam to get the lift I wanted. It was never because I actually dropped a valve guide.