460 vs 351w in the SN95 budget.

When budget is “ subjective”, it’s a no brainer. A351 dart block can be made to displace 454 cubic inches internally, and only take up the space of the external dimensions of a 351. The weight difference between the two is significant, with the windsor weighing at 510 lbs. and the cast iron headed 460 weighing in @720 lbs.
There is very little to do to make a 351 fit the car, requiring only the right headers and an oil pan, otherwise, the engine is a drop in. The aftermarket choices are numerous. Conversely the 460 doesn’t just drop in, forcing a re-think on the brakes, as the power brake booster will more than likely not fit. It’s heavy, it’ll require the heavy Hydro-boost system to bring decent brakes into the picture bringing the weight difference up closer to 300 pounds.
The transmission choices are similar,..While not as easy to find a 385 bell for whatever trans versus a SBF, it’s not that difficult.
When weight and fitment are not as important, Now days the justification for putting a 460 in one of these cars comes when considering a stroker kit for the engine, and going big. A 460 will easily accommodate 540 c.i w/o doing anything more than buying the right kit, and boring the engine .060 over.
However, when taking Saleen design objectives into consideration,..putting an extra 300lbs on the front end goes the wrong way.

Back on college, had a buddy that had a notchback with a 460 NA car. He used an aluminum plate to attach the entire front cut to fit mounts. I was inside bay with a sledge smacking out the tunnel so the C6 would fit. The hood closed just enough with the offenhauser manifold and air cleaner was flush with the hood, so nearly inconspicuous. That car looked like , but ran like a banshee. Can't count how many feelings that damn thing hurt.

Having done it more than once, if I was building a “ budget” drag car, and a going as fast as I can for as little money as possible was the goal...

There‘d be a 460/ C4 in the car.

I'll also support the 351W swap for your car as the 1995 Cobra R came with a 351 in it. But also, a Dart SHP 302 can support up to 385 CID if you wanted but the more common stroker for that block is a 363 which I have and love.