yes it will be ok.

personally if u want a better convertor go an impco model e.

i run a straight gas 425 with model L impco on my 351 cleveland.
made about 135rwkw threw an auto before it starts to die off but its the single mixer thats teh problem.

a 425 is only rated to 450cfm, the model e and l's are rated to 325hp from memory and the b2 is about 300
but the model e is just a nicer convertor and will run better

the model e has a better water inlet/outlet design and some people say they can make that tad more power too, but officially there rated the same just a different design to each other

iv got a model L because i had one laying around, if i was buying new id go E but it doesnt bother me that much

with about 300hp u probably will notice a drop off in revs

i actually picked up down low power, but lost rev's purely due to the lower CFM rating of the mixer.

so youll probably find normal driving u wont notice a difference but on a dyno you wont pull the same power due to the loss of rpm (rpm = hp) etc

the ohg x1 is bassically a b2 from memory, thats what lg coppied to make the b2