The engine you have now is about the limit of what you can do in terms of street power with a production block, hyd roller cam and production style heads. The issue is that you need to have the engine "on the cam" at 1800 rpm if you want to cruise down the freeway in overdrive. So if you're going to be "on the cam" at 1800 rpm then you can't have a camshaft with a powerband of 4000 to 7500 rpm.
The new engine that your are talking about won't work with a 5 speed OD transmission. The bigger ports, bigger intake, Dominator carb and bigger carb will not work at 1800 rpm in OD on the freeway. The air velocity will be low, torque will be low, and gas mileage will be horrible. That engine will work great starting at 4000 rpm and will make 700 hp at 7000 rpm, but it won't work pull a heavy B body down the freeway in overdrive at 1800 rpm.
If you want a 700 hp race engine then put a built 727 behind it with a high stall converter. If you pick the right converter you can drive it on the street and it will be a very fun ride. It won't be great for cruising on the freeway but that is just the way it is.
If you want 700 hp peak power and OD transmission then buy a Hellcat. That is what those engines are designed to do.
Thanks again for explaining this in detail. I now understand what you're taking about when it comes to driving down the freeway not being "on the cam" to use your words. With my current engine with a 252 // 258 cam the engine is not happy if i drop it below 2000RPM driving in 5th gear, I also got an Chevy El Camino (I know) with a 454 and a TKO 600 5speed with 262 // 272 solid fat tapped cam and that engine is defiantly not happy under 2500RPM in 5th gear at the freeway. At the same time I feel that both of these engines are fine (and fun) to drive around my small hometown with no problems leaving from 0 at a stop light.(only got one stoplight) I think what people put in the term street car // daily driver and expect in terms of manners differs a lot and how tiring it is to drive a radical cammed engine on the street al comes down to how much traffic it is where you live and drive.
After reading what you say regarding cam size and not going larger than maximum the 250 range I really wonder mow much more power a TF270 with a 250 range cam would make over the same set up but with the TF240 heads?
