Here's what I do know...I'll be buying a set of AFR190s and a LT4 HOT cam for my 1987 L98 with LT1 intake (8000 miles on .030 rebuild).

Here's my questions:
What roller rockers can I use with this setup? 1.5 or 1.6? self-align or non-self-align?

Do I need new lifters?

Do I need new pushrods? If so, how will I know what to get...how do I measure them?

I really need some specifics here...I know Summit sells some sort of measurement tool for the pushrods, but I don't know if it's necessary and what other pushrod lengths are available.

Thanks

 

The LT4 HOT cam is designed to use the 1.6
ratio rockers.. The AFRs will come with guilde
plates. If you're going to be spinning above 6000rpms,
You should stick with the non-SA roller rockers
and hardened pushrods.

As long as you're not changing anything to
affect the valvetrain height, standard length
pushrods will work ok.. (you may want to
check anyway, the tool is ~$20, the rods are
$100+)

Note that standard 1.437" AFR valvesprings are
not rated above 5500rpms, and you chance going
into valve float with the standard springs and
revs >5500. (which I suspect you will with the
LT1 intake..)

For reference, I have the AFR190s and LT4HOT
cam and I have:

CompCams ProMagnum 1.6 roller rockers (7/32" stud) non-SA
CompCams HiTech 7.200" Chromemoly pushrods
Crane 1.460" springs (983s) (987s also work)

GM 2nd-gen roller lifters are supposed to be a
a good hi-rpm lifter now that the Comp 875 lifters
are no longer made..

mike

 

I would love to rev over 6000, but my 1.5" primary headers are going to restrict me from making some serious power over 6000. The motor is in my all wheel drive S-10 (sitting on a 4x4 frame). Sanderson couldn't make larger primaries for the 4x4 frame because of shock tower clearance. I did ask AFR about those headers and I was told that my limit will be just under 6000rpm (about 5600-5800) because of my exhaust flow out of the motor. So I'm not aiming to rev past 6000 anyway...that would require exhaust work (again!) and custom headers. The LT1 intake is still going to be better than the high flow TPI setup I had. My motor was pooping out around 5000 with TPI...very disappointing.

Any additional thoughts now that you know a little more about my setup?

 

So it sounds like the basic package that AFR offers for the 190 heads will suit my setup perfectly (included springs not recommended above 5500rpm). Am I correct?

 

That's about at it's max, but should be ok..
The standard rocker studs are 3/8", so you
can just stick with them and get your RRs
for the 3/8" stud instead of the larger 7/16".

(The stardard AFR exh valve weighed in at
115g, the intake 110g. The heavier exh would
float on me at 6200, even with Ti retainers..)

FWIW, I believe this combo (MR/AFRs) will
make peak HP at 6500, so you will be limiting
yourself down at 5500.. (You'll be losing alot
of low-end TQ..) The AFR180s may be better
suited for you to help get some low-end back..


mike