3400/3500 hybrid

[kego]

so I'm selling my tgp motor to buy a 3400. if I'm going to do this I want to go a little crazy. budget is nothing I'm going to cry about because this build is one I'm going to work on over the years with my (unborn due in 4 days) son. so I have years to accumulate parts. I have a 90 z24 that I want a built 3400/3500 hybrid to go into. I've been reading here and there and putting what bits of knowledge I find together to form some sort of definite goal. I'm thinking 3400 bottom with forged internals (keep the crank but just have it touched up), 3500 heads using 3400 head gaskets and 3500 LIM and UIM with 3500 gaskets for that. its my understanding that there needs to be a custom mount bracket (in the front?) and various other things switched from one motor or another ie. alternator bracket, 3400 fuel rails grand am header/manifold blah blah blah. I guess what I'm trying to look into is if I use the 3.4 Camaro head gasket what would the max lift I could get out of the valves be before I need to think about different pistons? what cam would that require given the rocker ratio (that I'm not sure of 1.6 on the 3500?) then lets not forget about push rods. not sure which ones or if stock will work. I also plan on spraying meth. I touched on it as I was reading but it was less important to me than the rest. will meth affect any of the part specs I'll need to buy? I imagine to some degree I might want to modify specs on something. I cant see a bolt on that adds performance without needing supplemental something. I know that v6z24 (my home), 60degreev6 and jbody.org are great resources. this has been an accumulation of ideas from all 3 websites and I cant seem to find a thread that went after the exact same things as I am (I find this strange) if anyone can answer some of this can you also explain to me how you got there so I can follow along instead of taking orders? Haha thanks guys

[Guest]

Is this going to be a dedicated race car, or are you willing to allow the engine to warm up at idle for several minutes before driving EVERYTIME you take the car out? If you answered no to either of these questions, forget the forged pistons. Only use forged if you absolutely HAVE to, and for 99% of people out there that believe they need it, they don't. Cast aluminum pistons are good for daily driven and street applications.

You can't use a 3.4/3400 gasket with the 3500 heads, due to the combustion chamber size of the 3500 heads. Also head gasket thickness is really not a concern for valve lift, except in some extreme cases where there is large duration, and lift that can cause the valve to be open while the piston is nearing TDC.

The 3400 and 3500 already use 1.6:1 ratio rockers. If you stick with a stock cam then the pushrods should be able to be stock from either application, but I haven't not verified this personally.

Are you planning to run boost? If not meth will not usually be needed or improve anything, except for again is some extreme cases.

[SappySE107]

You can use 3.4/3400 head gaskets with a 3500 because they are 3.750" bore and the 3500 combustion chamber is no where near that size. Stock pushrods work for both setups...identical stuff. Head gasket thickness is best left where its at unless you change the pistons and they stick out of the deck more or less than what stock does for a 3400. Clearancing the pistons for the valves is a better way to go for performance than increasing the gasket thickness to move the valves away from the pistons. Depends on the cam you decide to run really. Forged pistons are fine if you want a custom compression ratio and you don't have to wait minutes for the car to warm up before you drive anywhere. Just before you try to beat on it would be a good idea. Worry about that when you get to that decision.