Hank Rutkowski, he is the author of Manual J7 and J8.
Your design temp at 1% is (88* DB/72 WB*). At 0.4 its (91* DB/73* B).What the means is the summer design temp will be exceeded only 1% of your cooling hours.
Using 70* indoor and 95* outdoor would be considered oversizing to me!
Here a couple of Manual J Don'ts
Do not design for record breaking heat.
Do not add a safety factor.
Do not design for abnormally low or high indoor temps or humidity.
Do not reduce known ceiling, wall or floor R-values "just to be safe".
Do not apply "safety factors" during any stage of the load calc process.
Here are a couple of does.
Use the outdoor design conditions recommended by Table 1A of manual J.
Use indoor conditions that are compatible with the comfort chart.
Verify all construction details prior to calculating loads.
These are a few of the reasons loads very from company to company. Manual J has a safety factor built into it already, Don't follow there guide lines and you mite as well use the square footage method.