Well.....I have 427 emblems on my hood...and there is a 540 under there these days!!
You might even have a steel 454 crank in there since it came out of a truck. It's just a shame to give up TQ by destroking it, especially since your hyd flat tappet, stock mainfolds and restrictive sidepip[es aren't going to want to rev high. PLEASe at least put some different mufflers under the covers....because the stock stuff is so restrictive it will kill whatever motor you put in front of them.
Still like a 4.25 stroke for what you are doing...especially with a hyd flat tappet cam. Since you aren't going to rev it, might as well pick it up with cubes and no one wil know if you don't tell them.
But back to the 427 stuff...you might check Professional Products...they had a bunch of new steel 427 cranks a while back for $149. I know a guy who used one in a 4.500 bore motor and spins it to 8600 rpm regularly with no issues.
A set of the 049 iron open chamber ovals will flow very well with some port work done. You might even have them on the 454 already. If it were mine I would use them with L2268 type pistons to end up with around 10.0 compression. They are usually 118-120cc heads without touching them.
The other advantage of going to the higher performance version of the pistons is they have a larger valve pocket. The 2300's get real cozy with a 2.19 intake valve in the radius of the valvepocket. 2.06's do OK, but upgrading oval ports to 2.19's or 2.25's during rebuild is a good thing.
There are also some strange oval ports that were used on 454's that say "Hi Per" under valve covers...NOT "Hi PERF" as the rectangulars do. They have small valves and hardened ex seats, but they have large oval intake ports. Easy upgrade to install large intake valves in. You can leave the 1.72 ex valves and hard seats for what you are doing. Again, any of these heads will really come alive with a little cleanup work in the ports. If you can find a machine shop with a Serdi machine, you can easily install the larger valves.
Just do calculations on head work..it's real easy to get awful close to a set of aftermarket aluminum or iron heads that will outperform anything you're likely do get out of the GM castings without a lot of work. Check Brodix race rites and Dart. Dart and World products make some very nice ironheads....but again...aluminum isn't much more.
Or just use some GM heads off E-bay...but beware you don't buy junk.
Block machining...shoot for no more than .040 total clearance between head and pistons. If you don't deck block, you can use steel shim gaskets just like GM did to keep it tight. Aftermarket gaskets are usually .040 to .050+ thick and they will kill quench. Tight quench is critical to getting good performance out of stuff like this without detonation. This is an area many rebuild shops overlook because it's "easier" to ignore it.
Which oil pan is that? The GM true LS-7 pan is an excellent one and works well if you are going for the stock look.
Plain 'ole Cloyes 3 position $30 timing chain set is fine.
Not sure if your $400 machine shop bill will include balancing, decking boring, honing, feeze plugs, cam bearings, cleaning etc. Much less head work.
Cam choice we will need to work on after everything else is narrowed down. Again if it were me, I'd use a solid flat tappet.....less trouble and no pump up issues. They don't need anywhere the attention people like to act like if set up right.
Plus we can get better street manners out of a solid flat tappet than a hyd that will run as strong. Even the GM LS-6 cam makes a nice street cam. Comp makes an "improved" version of it that helps.
I wouldn't hesitate for a second to go up to .600 lift range, but you will need at least long slot rockers to do it. They can still be stamped type, but you can also get rollers under stock covers with two gaskets.
Since you are doing a 427/435 clone...I know many folks just bolt the square port intake on the ovals. but I couldn't do it without doing some severe port work to blend the big runners into the ports. Not too hard to do really. Too much of a mismatch otherwise.
I'm looking at an article from a recent Engine Master's book. They built a 427/425 for a Vette, then played with it.
First, using 2300 pistons and rect iron heads and the Comp version of the LS-6 cam, 427/425 intake and a 780 Holley and cast iron ex manifolds, they made 455HP@ 5900 rpm and 460 ft [email protected]
Then they added a Comp hyd roller 236/244 .521/.540 lift and some GM/Edelbrock rectangular ports along with a Victor Jr intake and 850 carb as well as headers. It made 508HP@ 5800 rpm and 480 ft lbs@ 4700. This combo "hung on" much longer.....as rpm climbed.
Next they slid in the Comp 288AR street solid roller cam and a set of AFR 305 cc heads. Otherwise all the same...made 596HP@ 6500 rpm and 520 ft lbs@ 5500 rpm. This "nasty" version made as much low end power as the 'stock" one did and was up over 150-175 hp at high rpm.
I can tell you the 288 street roller is a fantastic street cam. I ran it in my last version of my 427 with merlin oval ports.
Anyway, hopefully this gives you some ideas...as I said we can narrow down cam later.
But do the math.....get a stoker crank and pistons and rods for the same price as the 427 stuff almost. Use your 454 balancer.
Or save LOTS of money and use your crank, balancer, rods and just get the piston kit. Put the savings toward a better set of heads or cam setup. Gain cubes and power!!