Jay, the 268H is a big jump, but an intentional one.
Let me explain.
This build was originally supposed to be just a stock rebuild, while I look for a 292 core to start a big build on. My intention was to kind of keep costs reasonable, but optimize what this engine has as much as I can. When it became obvious that the old cam had a badly worn lobe I knew I was going to put an "optimized" cam in. Whenever I have to pull a stock cam out, I don't put another stock cam in, makes no sense to me. So I was happy to find the mildest Comp cam that was designed to run well with EVERYTHING ELSE being bone stock. Just what my original plan called for.
I had a few self-imposed constraints to work with: time and money mostly. I wanted to get the car back on the road this summer (2013). It's been parked for 2 years now and I'm dying to drive it. Well that schedule set certain budget limits for the build.
Fast forward to today: due to several minor things working against me, and a surprise addition to the family that needed a partial motor rebuild (Chevy Aveo, don't laugh), I gave up on my target date of this summer. So that automatically buys me at least the whole winter time wise, and this means I have time to save more money for the build too. Plus driving the Aveo vs. my Jeep saves me a TON of gas money that I can now redirect to the engine build! So I optimize things a little further. I managed to find more compression by zero decking the block in addition to milling the head, I originally thought I would have to settle to something less than 9:1. But now I have 9.5:1 which could support a bigger cam. Again for the sake of optimization I decide to do the lump port modification, especially after running into a cheap set of lumps on Ebay. I do most of my metal work and engine building myself, only farming out some milling. So it's "free" labor.
As my plans evolve and I am able to throw more money at this project, and especially after spending more money to build an engine that COULD make more power... I'm now asking myself, "So why don't you LET it make more power?"
So the almost-stock 240H cam will need to be replaced with something MUCH more performance oriented, that would still work with my compression, carburetion and exhaust options and stock torque converter. So I would not want "the next" little cam, but a clearly hotter one.
I am not afraid of BIG cams, I have built engines with cams so big they had to be custom made, you couldn't buy those numbers off the shelf. They just require high CR to make them run right.
My cam grinder showed me profiles that he had designed, that require 20:1 compression ratio. Gasoline, not diesel. "Can't be done" is the first thing that comes to most peoples mind. But that's another story.
This means stepping up my game and spending even MORE on the build, not just switch the cam out at the last minute. I'll have to make the valve train stronger. Simple stuff really but another 300-400 bucks more. I can justify it because it would make all my other optimization work more meaningful. I was doing a lot of high performance tricks for a stock rebuild. Makes no sense to most folks but that's how I build them. But it IS kind of a waste. Now it won't be. With the bigger cam and higher state of tune, it is all well justified and fits the changed build plan just fine. AND I can still go back to the smaller cam later if I feel like it, without making changes to the engine.
About the SBC springs, from what I have learned, they won't work with the 268H. So be it.
Can't wait to get my head back from the shop to start measuring and mocking things up for .499 lift instead. Sometimes the journey is at least as exciting as the destination, if not more so for me.
Not %100 sure on the cam choice yet.
As for trans and axle, I will be killing all the fun with the stock 2sp powerglide and stock rear for now. First the engine, then body work and interior, and then maybe trans and rear. Being an automatic, I don't care what it is, it'll always be a buzzkill. For me, a performance car has a manual transmission. And they can corner. And they are light and nimble. THIS car is a heavy 4 door ocean liner.
Edit: my weekend warrior is a stroker big cam custom 68 VW beetle convertible. I just need to ship it from my parents house to me, some 6000 miles. It has maybe 1500 miles on the engine and it will run circles around any Nova.
