Originally Posted by runway1589
i was wondering if i can atleast get 300 hp out of my 86 caprice with a 305? or would it cheaper getting a 350 and buildng from the ground up? i know to replace headers and other parts but what parts would squeeze the most power outta my 305 without boring the cylinders. thanks in advance
Cheaper to build a moderate powered 350 at 300 horses and it will have much better street habits. The 305 pushed to 300 horse will require more and less street friendly tricks that raise the cost and reduce comfort range.
Like any engine, the cam and heads are the key. But pumping up an old engine usually results in other problems related to age wear of the bottom end. These type top end modifications on a high mileage engine usually result in excessive oil consumption from the get-go and bearing failures a bit further down the road because the pistons, rings, bearings as well as the oil pump and other bottom end parts are worn out. The engine has been loosing power for years so the stress and strain on these old parts has been going down. When you put a big cam and better breathing heads on top of these old guys they just get pushed beyond their current capabilities and quickly loose whatever life is remaining. Automatic transmissions are the same way, they wear about the same rate as the engine, so when you add power to the engine or replace it, the old automatic's life becomes measurable in weeks to a few months.
This is just not easy to pull off on a shoestring budget, which is why I recommend just buying new or rebuilt replacements rather than trying to piecemeal these jobs as the major components will usually die faster than the bank account can be rebuilt and you find yourself with a broken, non running car and no more money all at the same time.