What is needed for a street motor 455 500hp then 600hp?

This discussion was never about mild. DO NOT GET OFF TRACK.

The plan offered here is about having more torque than a flat tappet cam can offer including those with 110* LSA and having that torque over a wider rpm range.
We are looking at over 500 ft lb of torque from below 3000 to over 5000 rpms with peak around 550 ft lbs
We even showed a dyno sheet with similar results only with a smaller engine with a slightly smaller cam than suggested.
We are still expecting horsepower in the 500 range just not 600.

All of this back and forth buries the post that are of interest to the OP and leads to these side discussions that are not relevant except to show how to take a path of compromise that will have less of a result.
The Title of this post is "What is needed for a street motor 455 500hp then 600hp?"

If using a 700R4 you can use a little higher stall converter since it can be locked up in the higher gears at low rpm.
The proposed engine would smoke tire easily even with 2.93 gears.

 

Seriously ,...talk about over thinking things....

 

I am reading all the comments and learning more about the compromises of engine building. To narrow down my build I have decided on using these key components.
The goal is 500hp minimum and 600 maximum with rpms maxed at 6000 with a usable torque band for cruising/rough driving.

Edelbrock heads (mild port or full cnc tbd)
Ta 288 92h flat tappet cam proven 500+ hp capable (I can upgrade to roller later on if I so choose)
1800-2000 stall converter
Rhoads v max lifters (to aide in low end torque, and vacume)
ta oil mods
Either my long tube headers (needs work), or TA shorty headers with a x exhaust. I am familiar with the setup although collector and x pipe collector diameter being the same size I wasnt aware that's the key.

I am going to use a th400 for now. Cost being a big consideration, however I can upgrade it to a 700 later on.

The rear end is more of an annoyance then problem. I have no intention of slapping drag radicals and racing every weekend. That being said if the rear blows out I can source another rear end, or mod another rear in. Having a selection of gear ratios would be nice, but having highway gears is almost what the doctor ordered (So long as my lockup rpm is lower then cruising rpm).

The parts I'm not sold on or unsure about still include

Intake manifold TA SP1 or Ede. Will the low end loss with the sp1 or top end loss with the ede really make that much difference. Considering BBB make torque for days, torque generation isn't a problem imho.
Making sure the cam and converter work in conjunction with the rear end gearing does. My Electra weighs about the same as a late 90s half ton pickup with 2.93 gears. Having all that torque off idle would be great for towing or lugging Mrs Daisy around town, but that's not how I drive. A 1800-2200 stall with a intermediate performance cam, and rhoads lifters to help the low end.
Porting to help get max hp with the cam, while sacrificing throttle response is ok with me. If cnc porting and the sp1 prove way to much ille slap a b4b intake on and restrict the intake flow.

 

What pistons and compression ratio?

 

Dual plane would be a good idea.
I don't think the Rhoads would help so much using a SP intake...but I've never tried that.
I'd definitely keep the thm400 and maybe put that $$ towards a rear IF you need to.
Good plan!

 

I am using wiseco PT055H4 pistons. The deck was milled 20 so I can get optimal compression with the right head gaskets, but haven't plugged the cam or piston specs into that handy calculator yet. Lol

 

If you don't change your rear end gearing or raise the stall some, expect it to be a little lethargic below the cam's wake-up point (Rhoads lifters would help with this, of course).

Remember that Rhoads lifters will make some chatter (similar to solid flat tappet), so if that bothers you, you may want to opt out of that and have a camshaft that caters to the RPM range you wish to drive in (both cruising and performance). In this case, it's better to go on the smaller side of performance with a cam that has a wider powerband so it doesn't suffer as much below or above your peaks.

Otherwise, I'd say that the SP1 would work with your idea. The SP1 has good runners to keep velocity up for lower than mid range retention of power, and with heads that have good velocity, the larger cam would behave better down there as well. In the upper RPM range, you could expect to see less peaky behavior and a flatter HP curve.

It sounds like this is the way you'd rather go, and would work well with your other components, with room for upgrades later on if you choose.

You're on the right track. Keep up the good work on your research! :TU: