i had my engine rebuilt this summer, it was a lg4 305 with some big *** holes in the block from flying rods (how did that happen? i mean racing doesnt do that does it?? Anyways when i got it back i noticed that my car had a lot more power than before and the tach seems to be almost 1000 rpms off, it reads around 1500 when it should around 700. could they have mistakenly put a 350 in it? or do i just need to adjust my tach?

 

It woulden't matter what size engine was put in. the tach runs off a distributar(sp) signal, as long as you have the same # of cylenders it will still work right, so I' say either your wiring is messed up or the tach is. as for the engine size MOST latter 350 blocks have 5.7 stamped on the top back of the block (ya know that point where the tranny mounts- to the passenger side of that) hope this helps also you can look up the engine code wich is located on the top of the passenger side water pump mounting boss (bring a wire brush- paint likes to cover up the numbers.

 

the engine in it before was an lg4, but considering the block was destroyed, and the shop i took it too gets their engines from somewhere else, i just wonder exactly what i have, i know its not an lg4 becuase it has way more power than it did, but maybe i just got a newer 305. i guess theres no way to tell.

 

see this web site http://www.nastyz28.com/sbchevy/sblock.html it has all the engine codes and where they are.