Questions on Hybrid 3.1/3100

[91z24build]

Hey guys,
I just have a few questions about my hybrid build. I am using a 2000 model large port 3100 on a 3.1l block with a lunati H260 cam. My main question is wich pushrods (3.1 or 3100) will work best with the flat tappets from the 3.1 and the topend from the 3100?

My next question is about headgaskets, I would like to bump the compression slightly. What headgaskets can I use to accomplish this without having to modify anything?

Thanks in advance.

[IsaacHayes]

I think you'd use the 3.1mpfi ones, but they won't be perfect. Don't hold me to that. Headgasket, not sure. You could do an iron head 3.1 probably, but might risk the valves hitting the pistons but I think fallenz24 did that and was ok, so YMMV!

check domesticcrew.com for hybrid instructions about the pushrods...

[RedBird]

for pushrods, you need to measure the get the length just right.... couldn't tell you if one would work better than the other though, i don't know much about hybrid swaps.
You should be able to use ironhead 3.1 HG's no problem. the 260 isn't too big of a cam so i doubt .020 less clearance is going to affect piston to valve clearance.

[IsaacHayes]

Fallen had a stock cam IIRC FWIW. Remember to get some good strong valve springs for that cam so you don't get float. Rods stretch under high RPM so that could cause trouble if you have tight clerances with the valves.

[ForcedFirebird]

The heads you are using, do they have adjustable rockers, or the pedistal style? Either way you should be OK with a new cam and the stock 3.1 pushrods, but measure to be sure - they workd on my 3.4/3500 hybrid perfect with a new cam (re-grinds have a smaller base circle).

[91z24build]

How do I go about measuring the pushrods with hydraulic lifters?
The lift at the valve with this cam and 1.6 rockers is .470
Already got a set of K-motion springs 120lbs @1.7 rate is 464.

What is the compressed thickness on the iron head gaskets?

[IsaacHayes]

.040"

[sanjay]

I have the same hybrid and I'm using the 3.1 pushrods. It works just fine. Now I've only put 250 kms on it and It's only gone past 6000 rpm once. It's in storage now but I'm looking to put another 750 kms on it in the spring to finish my clutch break in and then it's gone in favor of a stronger setup. If your question is will it work then the answer is yes. If your question is will it work OPTIMALLY well assuming you're not converting your heads to gen 2 (or early gen 3 3100) adjustable rockers then you'll need custom pushrods for proper preload. The 3.1's will work if you have budget to keep but I can't say anything for long term reliability. I can however say that my hybrid pulls considerably harder then a gen 2 top end over 4500 rpm and mine is untuned.