340 timing cover HELP

**JEREMY WATTS** · 06-15-2011, 05:35 PM

Hi all, new here and just wondering i have a 67 lesabre with a 340-4 in it we just bought the motor was siezed up completly, i have another 340 that i am building to replace it and so far every thing has gone very well every thing bolts up perfectl ie intake, oil pan but the timing cover has one difference that worrys me the engine i took it of of ( the one in the car origionaly, has three bolt holes around the two main water jackets, the new block only has 2, can any one tell me what i need to do is there a different timing cover i need to get or what. any help would be appriceated greatly. thanks

**Tommie** · 06-17-2011, 05:24 PM

Bad news. You have the wrong block. It sounds like you have a 66 or maybe a 300. Check and see if it has "340" in relief in 3 inch numbers on the bottom right side of the block. I just checked my spare cover and it has the 3 holes and both my engines are 1967 340-4 s. They put 3 for a reason. You could drill and tap it maybe, but I'd leave that to a machine shop.

Call me if you like on Monday at 732-380-8246.

Tommie

**JEREMY WATTS** · 06-21-2011, 07:17 PM

Yep they both have 340 on them , thanks for the help though

**Tommie** · 06-29-2011, 12:45 PM

Jeremy, sorry I couldn't be of more help. Not much support out there for these engines. If you need intake manifold flange bolts, I have new ones!

I have also seen new timing chain covers on ebay and NAPA has them. Not sure if they are 2 or 3 hole..

Tom

**JEREMY WATTS** · 06-30-2011, 08:34 PM

thanks anyway

**4drgoner** · 10-22-2011, 01:02 PM

The two bolt hole configuration it an early, early 340 that would have been produced prior to the month of march of 66. you can either tap it, (comeplete pain though) or the easier route it to see if you can get a 300 pump in your area. the length is the same and wil keep you from having to potentially ruin a good block. the other thing is a 340 will accept an overbore to a 350 piston. the cranks and rods are the same between the 340 and the 350. The downside to doing this is that the 350 piston will reside quite a bit deeper in the bore, thus neccesitating a quote higher ratio piston to come up with the 340 4V's stock 10:25 to 1 ratio.