i've got my 305 set up with a zz4 cam and heads, and i've been considering getting 1.5 roller rockers. my dilemma is that the zz4 has a lot of lift as is, and i don't want too much lift. will i have too much with 1.5s?

 

1.5 is stock. No problems there.

 

Yes you should replace the springs for the ZZ4 cam.

 

my bad.
1.6s might be a bit radical, though. correct?

 

Not if you replace the springs to accomodate the upgrades.

 

1.6 rockers are a good upgrade to that setup because the L98 H.O. heads increase flow up to about .600 lift, but doing so will require an upgrade of your valve springs. i believe those ZZ4 springs will coil bind at that much lift. what i would do is port those heads as well. the combination should yield a substantial increase in power.

 

i would change the springs to use 1.6s but not for the 1.5s.

 

80smetalfan

You also need to check retainer to seal clearance and pushrod to head clearance since the pushrod is moved closer to the pivot point with the 1.6's.

How do you like the ZZ4 cam. I'm thinking of installing one in a 350.

You can't beat the price of the cam ($95) new!

 

as far as the 1.6s, the pushrod to head clearance was the main thing i was worried about, and even if it clears, but it's close, i think it's too much lift for my engine to really utilize, i don't think my heads and intake flow well enough. though i guess if i ported the heads and some of the stuff on my TPI, that might really pay off. i don't think ( ) the springs would coil bind, the 113 (zz4) heads have LT4 springs.

as far as the zz4, really, i think it's a pretty good cam, especially for the price. i mean, if you're building something just for racing, it's probably too mild. but i think it's a pretty good cam for just street usage, maybe even light street/strip usage. it makes pretty good power about 2000-5000, which people stuck with a stock TPI will really appreciate. i personally think it would really be a good cam for a 350 TPI, cause the 350 makes so much torque down low, especially with TPI, and the cam would really complement that well. it's got a pretty mean idle too, at least on my 305. and as you said, the price is hard to argue. if you trust eBay, i'd look there too, i've seen 'em as low as $50!

 

well if memory serves me correctly the LT4 springs have a max lift of .525 and the ZZ4 cam has .510 on the exhaust side. so...with 1.6 rockers thats going to put you at .544 which exceeds the capabilities or your LT4 springs. yeah you would need to upgrade springs.