The rover v8 which I have an sd1 version with the all alloy construction was the first v8 to be built like this by Buick in the 50s , rover bought the plans because Buick could never fix the head warping which rover did.
The lowest bhp is about 138/168 going to 200bhp in the vittesse and 300 in the twin turbo it's a lovely motor but the more bhp and displacement you get out of it the more fragile it is.
It is a push rod v8 after all the racing 5.0 got over 500bhp but never lasted very long.