My $.02... forget using a hydraulic roller; buy good solid roller lifters with force-fed pin oiling

The "if it was mine" answer is... you haven't outlined enough of your performance goals / objectives to talk cam specs, yet

I'm currently in the planning stage of building a 400 stroker (4.250 stroke) for my 69 Roadrunner 5 speed (TKX) .
I would like to hear opinions and suggestions when it comes to selecting a camshaft and lifters for this build. The goal is to build a radical NA street engine that takes full advantage of the TF270 heads with 10.8:1 compression and a hydraulic roller (HR) camshaft.
I'm looking for some advice when it comes to how much camshaft / spring that I would need to take full advantage of theTF270's at the same time as it needs to survive on the street for at least a couple of summers:-)) The engine will be built around the following components: 230 casting 400 block (thick web), 4.25" stroker kit, TF270 heads, Indy 400-3 intake that will be ported and matched to the TF270's by Wilson Manifolds, Holley 1050cfm carburetor, Harland sharp 1:6 rocker arms, TTI 2 1/8" step headers. I'm currently looking at a HR camshaft with the following spec: 266/270 @ .050", .629/.635" lift with 1:6 rockers, 108LSA, spring pressure closed 155#@1.880" open 415#@.650" My question is really if this cam / spring combo will survive on the street? Will a HR lifter with its weight support the powerband of a camshaft and head combo like this? If I go HR what would be the best HR lifter to use in this combo? Is a solid roller an alternative? Would a solid roller survive on the street idling around 1000-1500RPM?

I don't think it is possible to take full advantage of the TF270 heads with a Dominator carb in a street car that has a 5 speed OD transmission. I just don't think any engine builder can do that. A Dominator carb and a big cam will not work in a heavy B body car with a 5 speed manual transmission. You'll be dumping raw fuel out the tail pipes if you drive that combination on the freeway in overdrive. Any camshaft big enough to take full advantage of a TF270 heads and a Dominator carb will have too much overlap to play well with an OD transmission on the freeway.

You need to rethink your combination and/or your goals.

I don't think it is possible to take full advantage of the TF270 heads with a Dominator carb in a street car that has a 5 speed OD transmission. I just don't think any engine builder can do that. A Dominator carb and a big cam will not work in a heavy B body car with a 5 speed manual transmission. You'll be dumping raw fuel out the tail pipes if you drive that combination on the freeway in overdrive. Any camshaft big enough to take full advantage of a TF270 heads and a Dominator carb will have too much overlap to play well with an OD transmission on the freeway.

You need to rethink your combination and/or your goals.

I'm totally with you on the Dominator carb criusing down the freeway in 65mph on fifth gear not gonna work. If going the carb. route would Indy 4150 flange 400-2 max wedge intake with a good Wilson port job and a Quick Fuel 880cfm vacuum secondary carb. be a restriction that will hurt the air flow so 700-750HP is no longer in reach?

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.

Sounds like you want to build what i built. A 511with 11.25:1 compression street deal, but i used a 270@50/.625 on 110 solid flat tappet. My heads have 330cc ports and flow in the 350's@.700 lift. I went a best of 10.06@134 in a 3300# A body street/strip car(full interior). I use a 727 with a 5400 10" stall vert. I wouldnt want to drive it across the country, but you could drive it most anywhere. i kept it within 50 miles of my home. It did have a 1100 Dominator that was so reliable and the best street manners you could ask for. It did cruise down the freeway without issue other than getting hot because of a cooling issue i have at speed . i could let the car set 4hrs and just hit the start button without pumping it and it would fire up and idle. Dominators can live on the street, but you have to get them from a good source. Dom@Thumpercarbs can give you a Dominator that can do both street and track very well. Dom builds the best hands down IMO.
I now have a solid roller in this combo with similar specs, but on a 108. I use the oil thru lifters from BAM, but best tells me not to make a full pass because it will empty the pan. I did not bush the lifter bores in this block and i guess that is an issue with using stock blocks without bushed lifter bores using oil thru lifters. Did not know that at the time. I figure i can still run it thru the 1/8 just to get a time on it. I have also traded the Dominator for a T ram and 2 more of Doms carbs these being 750's. It still have the same great street manners. Dominators and T rams can live on the street just fine, dont let anyone kid you about that as i have videos to prove it. Oh, one more thing, i now have 12.5:1 compression and it still drives on the street just fine. I just run better fuel and it smells better.