My 69 GMC LWB has an original 307 (according to Mortec),.. is this right??

[tripleblack]

To my surprise, after i hoisted my engine out and was able to see the engine block number, i looked it up on the Mortec website and it was a 307, opposed to the 350 that the person who sold me the truck told me it was. Any insight, and how much better, or worse, is a 307 compared to a 350??thanks.

[Ron 586]

They are not what you want for a high performance buildup. I don't have a problem with them as all that I've had ran good and got better gas mileage than my 350. My orange 72 lwb has one in it with 110000 miles and still running good. If you are going to just drive it your truck it should be fine. If you plan on building a hot rod or towing a lot then you might want to change.

[MrGoodpliers]

I agree with Ron. The 307 is a great little motor for economy but not so much for towing or performance. During this period, Chevrolet was just juggling parts to make different combinations. The 307 is basically a 283 block with a 327 crank. The inverse of that is the high winding 302 (327 block and 283 crank).

[pissonNOS]

probly is right my truck had the original 307 as well, ive done mods to it and it keeps up with mosty 350's around my area i think there a good engine

[JAKES 68GMC]

Yours must be a REAL good engine. Look at that burnout.
I think 307's are under-stimated. They have 200hp stock and 300 ft lbs, and a lot of them found there way into 3/4T 4x4s.

http://www.67-72chevytrucks.com/vboa...ad.php?t=69324 All about 307's.

[Longhorn Man]

Most of the time, when some one doesn't know what there small block is, it gets called a 350. Just like 75% of the 327 engines you see, will be called a corvette 327. People tell people what they want to hear.