455 AND 403 ENGINE REBUILD Our engineering team has rebuilt many of the Oldsmobile 455 and 403 cubic inch V-8 motors that are used to power our GMC motorhomes.Please contact us for an appointment to have your newly rebuilt engine installed: Contact Us
When we rebuild the engine, it is done with your original block or with a block that we have professionally pre-prepared.We typically install new parts: pistons, camshaft, lifters, double-roller timing chain, crankshaft, rings, bearings, oil pump, fuel pump, water pump, brass freeze plugs, and all seals and gaskets.The remanufactured heads will have new valves, valve guides, springs, seats, keepers, and whatever else they may need.The engine block will usually be bored to .030 inches over-size. This assures that the new rings and pistons will have a perfect fit.One of the strongest features of the GMC Motorhome has always been the Oldsmobile 455/403 engine. Over the years, we have seen that most GM enginesgo trouble-free for much more than 150,000 miles. Even at 100,000 miles, most engines may only need a new water pump, timing chain, distributor, or possibly a valve job. We will do several tests to determine just how worn your engine might be before replacing or rebuilding it.