MG Sports Cars

Any ideas I am rebuilding a MGB conversion with a 3500s 10.5.1 engine P6 and eldenbrook 4 barrel. Any idea of HP . This engine I think has more hp than other 3.5 rover engines so is it a good choice or should I look for another 3.5

Welcome to BritishV8, Robert!

Rest assured that the Rover P6 variant is just fine, and no stock BOPR 3.5 has a significant performance advantage over it. 10.5:1 is a nice static compression number, if that's what you really have after rebuilding. Just make sure you're starting with undamaged parts, and then go with it. Focus your attention on doing a good job. When you outsource work be carefull to choose good shops.

But polling strangers and asking them to guess horsepower numbers is a waste of time, for countless reasons.

It sounds like you may still have many decisions to make concerning how to build-up your engine. Which camshaft to use? Or which pistons for that matter? Etc. That stuff can have a big effect on horsepower, torque, and "the area under the curve". All the little parts are important too, but for reliability. You'll find all sorts of good advice about that stuff here.

It's been over 30 years since I built my Buick 215. I've driven it in 46 of the United States so far. I've driven it in countless autocrosses and on track days. I've let a whole bunch of idiots borrow and thrash it. Everything from the camshaft downward is unchanged, whilst I've upgraded everything above the cam. No problems (aside from period-correct oil seal leakage;) because these are great engines. Driveability and reliability depend on quality work, so that should be your main focus. That, and enjoying the whole process. Have fun!