The flywheel bolts on 1993-2005 Northstar engines are weak. First of all GM used M8x1.25 bolts, which is almost unheard of for an engine with this much power. What's even worse, they used a metric grade 8.8 which is not very strong. We sell an upgraded bolt with a grade of 10.9 which is much, much stronger (about 40%)- which means you can torque these slightly above stock spec and they won't stretch.
2006+ Northstar used an M10x1.5 bolt, which is much more robust and does not need to be upgraded. If you're working on a 1993-2005 model front wheel drive Northstar, it's very good insurance to buy a set of these and install them during your repair- because if the stock bolts get re-used, and they stretch, the engine is coming back out to access these. Oh, and we also sell new flywheels, too!
$22.00, shipping included along with any other order on our website. Sadly due to high shipping fees, we will not sell these individually unless another order is placed on our site.
*****Installation Note*****
Make sure you throw a generous amount of RTV sealant on each one of these flywheel bolts before they go in, or you WILL have an oil leak afterward. The holes go through the crankshaft, into the bearing area. This is true even if you re-use the stock bolts.
