Ok to stroke a 351W to 393 cubes do you have to keep the cylinder bores to .030 over or can you go more? I plan on doing the stroker for my truck but I haven't heard if you can go to .060 over on the cylinders or not. I have a 351W that I believe is at .060 now. That would make my current engine a 362 correct? Anyway, I have a friend who said he would sell me a 351W that is out of a 78 Cougar if I couldn't use my current block. I belive that I would probably end up having to get custom pistons made for the engine with this setup. Unless 302 pistons are available this large now. I don't have too much experiance with 302's as far as cylinder sizes.

What I plan on doing is buying a set of cast iron GT-40 P or World Castings heads from summit. The GT's sell for $270 a peice and the Worlds are $390 per. I haven't totally decided yet. Pro's and Con's anyone? A SCAT 9000 stroker crank, "H" beam rods, ARP main/head studs, a stud gurdle,and the cam is still to be determined. I still want to be able to drive this thing daily. What else should I take into concideration. I have thought about the intake and my choice is leaning towards a dual plane design. Mainly I will be driving it at 2000-3000 daily with trips to the strip on weekends. I have a Crane XR-700 ignition, Carter High Volume fuel pump, Edelbrock Streetmaster 351W intake, and a Holley 4150 600 cfm carb on the engine now. I believe I will end up bumping up to a bigger carb due to the added cubes. Anyone have some thoughts? Yeah, like I had to ask that. Any thing I haven't thought of that may need to be address before I start buying parts? Well thanks for reading this far.

 

Well, your solutions are not that complicated at all. As for 302 pistons, they can be ordered "off-the-shelf" in .020, .030, .040, and .060 from just about anyone offering 302 pistons. The 351W 393 stroker does not require anything in the way of a "custom" piston, just a 302 piston. Your overbore dictates, of course, what size (diameter) piston is required. If you opted for a set of Twisted Wedge or Yates-style heads, THEN a custom piston would be required. But, as far as the GT40's or Gt40P's and World Products heads are considered, all will match up great. Boring your 351W .060 is not a bad idea, however, if you plan to punish the motor occasionally at the strip, I would recommend Sonic Checking the cylinders, making sure they are thick enough to handle the extra torque/horses. Personally, I would use a relatively fresh, unbored block as a starting point, bore it .030, leaving the jump to .060 for a later rebuild. (hopefully a few years or more down the road) As for the rest of your bottom end parts selection, sounds like you have a good grasp on what will be needed. The heads are a different story, to a degree. Of the choices you listed, I would select the World Products versions. The reasons, basically, are: They will bolt right on, you mods necessary. The flow ratings are good for your combination. The Gt40P's won't have the same flow numbers out of the box as the World heads, so port work would be requried to make them flow as well. Also of note, you may have a bit of interference with headers-to-spark-plugs with the GT40P's, as Ford relocated the plugs for a more efficient chamber. You won't have this problem with the World heads. The GT40's are similar to the World heads, the only difference being that the World heads flow better out of the box than the GT40's. One more item to remember on 302 pistons: You should opt for a piston with a relatively large dish to keep compression to a respectable, liveable level. The extra stroke will boost compression ratios in the 351W/393 stroker. Keith Black offers a nice hypereuctectic piston for this application, with, I believe, a 22cc dish. Your final compression ratio, depending on deck height, chamber size, gasket thickness, etc., will be in the neighborhood of 9.0-to-1 to 10.0-to-1. Good for pump gas and daily driving. And lastly, but certainly not least, your cam selection. Please, if you listen to no other advise on the planet, listen to this: Call a Cam Grinder, not a saleman, and ASK about what cam is best for your combination/vehicle. Be prepared to answer a ton of questions about your engine, flow data, vehicle weight, trans type, etc. Too many people have learned the hard way picking the wrong cam and experiencing a motor that just didn't live up to expectations, which can be mighty depressing and cost even more to correct. In other words, unless you are a camshaft guru, let the pro's pick one for you, you won't be sorry. Good luck on your build up, I am positive you will enjoy it, I have one myself. - Don

 

Thanks Don. I was talking to co-worker this morning he suggest the Keith Black pistons to me. Kind of surprised me that he has one built sitting in his garage that he has been building to the last 6 months. For the cam I was thinking of calling Com Cams for their suggestions. As for the block, my 351W has a decent .060 bore on it right now. I can get another one to build with no problems. I just wanted to see what other opinions would be. I was cofused when it came to the stroker block having to be bored out or not. I can use the standard 351W bore and get 302 pistons that are .030 over correct? I know the stock length 351W rods are used. Is there any sense in using the Mildon main caps that have the extra off set bolts? I can only think of added security when I take it up to the higher RPM range. I will also spend a little more for the World Casting heads. Makes no sense in buying a new set of heads and have to turn around and port them out. Thanks for answering me again.

 

A 302 and 351 have the same bore, so you have to bore the 351 .030 to run .030over 302 pistons. You absolutely do not need the heavier main caps, if you get over 500hp or so you can get a main girdle. Comp should be able to hook you up with good cam recommendations. As always, have every bit of info ready about the engine. Tranny, stall rpm if you run an auto, truck weight, gear ratio, etc.