I'm rebuilding a 92 3.8 V-6 in school and the rocker arms look identical to my '84 302 ones. The 3.8 V-6 have a 1.73:1 rocker arm ratio compared to the 302's 1.6:1 and the CougarNuts website says you can use 5.0 roller rockers on a 3.8 V-6. So I'm wondering if you could use the V-6 rocker arms on a 302? This would be a cheap alternative to buying expensive roller rockers. Has anyone done this before?

 

I compared the 5.0 rocker to the 3.8 rocker. The 3.8 has the pivot closer to the back so to make them work, you would have to make offset studs and ream out the pushrod holes.

 

That's how they improved the ratio, by moving the pushrod seat closer to the fulcrum. But using them could hardly be called similar to roller rockers. Most of the gain from going from 1.6 stamped steel to 1.7 rollers is from the frictional loss in the trunion over using a fulcrum. A tad more is gained from the increased lift, and little to none from the roller tips. If the 3.8 rockers are 1.73, they're likely the same units used on the 429/460 and 351C & 351M/400. I have heard that the 3.8's heads shared a few things in common with the Cleveland heads.

 

Since there is little to no gain on the roller tip,you could use them with the roller fulcrums crane makes for the stock rocker.

 

Have you priced the roller trunions for the stock rockers? Seems like the last time I saw them, it was more cost effective to just go alll out and buy full roller rockers. Good used sets of 1.7 "Cobra" rockers can be had for 100-125 dollars. I've bought two sets this way. One set's been on three different builds since I've had em.