Ok if i knew i wouldn't ask...SO! are one longer than the other and my 5.7 TPI is STOCK other than "breathing" help (headers/bigger exhaust) and what if any gains can i get from either one OR which one? I'm going with rollers with a oem roller cam.
thanks for some help

 

1.5s are stock.

1.6s are shorter on the push rod end, and possibly a little longer on the valve stem end. (depends on the specific mfr) But since they are ALWAYS shorter on the push rod end, sometimes they move the push rods far enough inward, closer to the rocker studs, that they bind on the holes. The cure being quite easy; pull the heads, have the holes machined out. (depends on the specific heads... sometimes even, on one head they'll work, the other they'll bind)

If you have an otherwise stock TPI, the amount the valves open isn't "THE" bottleneck, therefore gains from increasing valve lift will be minimal if even detectable.

 

i see....thank you sir

 

Going to a 1.6 rockers is a poor mans cam swap. you'll get better gains with a cam swap because so many other cam specs can be changed, not just lift. Duration, LSA, valve timing etc.

With everything being the same, if you swapped 1.5 roller rockers for 1.6 roller rockers, you would only gain about 5hp.

 

Man, so many choices....Aluminum? Stamped roller tip? Locking? Self Aligning?
Its a stocker, i just wanna free it up a little over time, It will never be a REAL hot rod just some nice stuff for the weekend cruiser/car gatherings kinda thing..so What do i want?

Oh Iv'e got headers on, and 3in + exhaust (cant remember) Will be grinding/porting/the intake plenum,intake and bigger runners so what cam will be ok after i have the Memcal programmed without Emission,lockout time changed etc?

 

Cheapest upgrade to free up some friction is roller tip rockers.

Some inexpensive low end cast aluminum full roller rockers will do just fine in a street engine. Self aligning depends on what heads are on the engine.

The biggest advantage to a set of aftermarket rockers is the precision ratio. A factory stamped steel rocker is nowhere close to a 1.5 ratio especially across all 16 rockers.

 

I hear too many horror stories about cheap aluminum rockers. When I upgraded the rockers in my Vortec TPI build, I elected to go with steel-bodied roller tip rockers. I chose PRW rockers after reading up on them, and so far so good.

 

I used Comp Cams stainless Magnum Pros for many years until a top end oiling issue hurt a bunch of them. I now run T&D shaft rockers and they're all aluminum bodies.

 

I'm going to the whole deal with Jessel's steel.$$$$but worth the cost over many laps.