Z 2 8

A buddy of mine was saying i should get an LT4 intake manifold and some 1.8 RR's. I've noticed that most people get 1.6. Why is that? Should i go with those instead? I would think 1.8 would be the best choice.

Also, how do i go about the LT4 intake manifold? Will it work and is it actually worth it? All i have now is a CAI, LT headers, Y-pipe, LT4 KM and a tune. I just want to make sure i'll get a gain with it.

foggedz

iTrader: (1)

Unless you have LT4 heads the LT4 manifold will not help you. 1.8RR would be a bad idea.

96capricemgr

iTrader: (1)

Your friend is into LSx motors isn't he???
For all practical purposed there is no bolton LT1 intake upgrade. The LT4 manifold has the same ports and plenum as the later LT1 intake so it would really really not be an upgrade even if you machined things to make it fit. Been covered with GIZMO being so kind as to post pictures of how the difference is more aluminum NOT more space for air to flow.

1.8 rockers are mostly an LSx thing not LT1.

You could maybe do 1.7 rockers depending on future cam plans but 1.6 is most often the right choice.

streetwarrior96

1.8 Rockers for LT1...... Only in Alice and Wonderland

Sgt. Spuds

iTrader: (1)

Instead of just stating the fact that 1.8 ratio RR's are a bad idea on a ltx based engine, why not explain it? I'd love to hear the reason behind it, as they work on lsx based motors, and their both cam in block GM motors.

96capricemgr

iTrader: (1)

Maybe if you understood that LSx motors are 1.7 stock as opposed to our 1.5 stock it might help a little.

WhyHelloOfficer

iTrader: (5)

I've tried searches on people running the 1.7s on the LTX and haven't really found an answer leaning one way or the other.

Assuming you've got valve cover clearance, would the ends justify the means on a cam only car?

96capricemgr

iTrader: (1)

1.7s on an LT1 are going to be best left too stock cams or HOT cams specifically, basically everything else already has enough lift that 1.6 is a good ratio.

WhyHelloOfficer

iTrader: (5)

http://web.camaross.com/forums/showt...&highlight=%22
Has a lot of great info on a 1.7 Install on a stock cam.

I'm currently running the hot cam. Now that I'm looking at the details and doing some searches on other sites. I'm thinking that it might not justify itself in the end. The LT4 springs are basically maxed out on the lift of the Hot Cam with the 1.6s. Allegedly LT4 Valve Covers are required to to fit the 1.7s without any modification.

That combined with needing new pushrods to make the valvetrain geometry correct -- I don't think the cost of the Rockers, Springs, Pushrods, and Valve Covers would really justify for the extra power. Especially when I could just re-jet my car to make up the difference

Z 2 8

So, would it be ok for me just to get 1.6RR's? Would the car run ok, or could that force me to have some problems? Anything else i should do?

Also, my friend does have a LSx motor. Which is why he probably thought that.

So, is there any other little mods i can do that will add up to another 10-15Rwhp?

96capricemgr

iTrader: (1)

I would suggest some basic springs with the rockers to make sure the valves stay under control, this is the one application the LT4 springs are actually a good candidate for, a stock cam with 1.6 rockers. Think they are only like $35 a set. Others will likely suggest more expensive springs in a "do it once" argument but a real cam later needs springs to match it and you would not be well served to use used springs at that point. In a performance application valvesprings are a wear item.

Revelation Z28

iTrader: (10)

you can run 1.6's on stock springs from what ive heard.

96capricemgr

iTrader: (1)

Can and should are two differnt things, 10 year old stock springs are weak and will probably float with the addition of 1.6s, the LT4 springs are cheap and by doing them now he tears it apart once rather than doing it again later when he finds out he is floating the valves.

Z 2 8

Good plan. Any idea on any other mods i could do?

Also, where should i buy the RR and springs and should they be new?

96capricemgr

iTrader: (1)

Ideally I would say 1.6, 7/16" ProMagnums NON-sa with GMPP guideplates(or Isky adjustable) and a set of 7/16" studs. That is the rocker/stud/guideplate combo most of us with heads and cam run, this way you could reuse all those parts later as your mod list grows.
Used rockers can be OK ProMagnums are rebuildable if you find them cheap that might be an option, not sure on what that costs though.

Springs get new, your favorite GMPP distributor would be fine.