Hey guys. I have an 80 f150 ranger with a 351m. I'm ordering Aussie 302c heads ando I can't decided on what cam do go with the comp 252 or the 268. All the truck gets used for is to play in the mud and haul firewood. I already have a wieand intake and a holly 650. I have stock gears and currently on 35s but planning to go to 38s in the futre. Also wondering if anyone knew if the timing chain set that comes in the cam kit is strait up or oe. Thanks

 

should be straight up, unless it has several keyways then you can set it up how-ever you wish. Dont know about the cam- but 268 is a good cam and if you ever have some spare cash and turn it into a 400 before the cam is shot it will be perfect for it.

 

There is no way with a stock botom end that you will be able to take any sort of advantage of the quench style chamber of that head. The stock pistons are way too far below deck at tdc, not to mention the huge dish in them as well. Not really the right way to go about building compression. I'd get a 400 crank & set of tim myers flat tops, zero deck it and run the stock heads with some port work.

 

If you were going to get new pistons. Get the ones to suit the Aussie heads and really do it.

 

I know going 400 is the the way to go but its not in the cards right now plus the bottom end only has 15000 on it. I just figured since I had to pull the heads to replace the blown head gasket I might as well put a better head back on and for $475 that's one hell of a deal. Thanks for the input.

 

.. X 3... I also vote for the inexpensive 400 conversion over putting anything into the 351M... and I have a 351M...

 

The 268 out of those two. The 252 doesn't have enough overlap for the high static compression it will be a detonating sob. Better yet the XE262 is what im running on my aussie head build.

 

.. There are two or three "Comp 268 cams"... the older basic 268 is a 218/218... the latest XE268 is a 224/230...

.. The 218/218 is plenty big for your tire diameter(s)... the 224/230 won't want to pull hard till 2500-3000 RPMs, OK for a light car where the engine can grab its way to high RPMs quickly, but could be soggy for a large truck on big tires depending on axle gear ratios...... the split duration XE262 would prolly be best of all...

.. I'd still keep the stock heads and put the money into a 400" crank and TMI/KB flat top or domed pistons for much more satisfying results...