I would just bump the dose of test....
But if you insist on adding another compound, then I would try test/tren.
You could go several routes
High test, moderate tren... 500mg test, 400mg tren
Low test, high tren ... 125-250mg test, 600-800mg tren
I had sort of disregarded the high tren/low test stuff, until recently. Now a LOT of top name powerlifters in the US are discovering that this is what has been going on in many Eastern European countries for years.
They are going high tren, or high deca, or high EQ with low test and it is working very well for everyone I know who is trying it. Apparently they are also finding that EQ year round (obviously for cruise/blast guys) gives good strength gains, and that it really seems to start helping around the 16-20 week mark. Granted, this is fairly new to my circle of friends, and I may be repeating things that have already been known, but they are loving it. Far less sides, and better results. One dude is using 2 grams of EQ, and a gram of tren with 100mg test and went from around 290 to 310, and is significantly leaner now.