351w long block vs short block

[duganfife]

Alright so I have a 74 bronco with a 302 (odometer says 80,000 from PO) and a c4 trans, 2 inch body lift, rockcrawler steering box, toms disk brake conversion, everything else is stock. I just got a couple grand from school and want to do a good engine build.....this is my daily driver in the DC area...I have several questions:

1. I don't think it is worth rebuilding and boring a 302 vs the swap or is it?

2. Because of already having the 302 and many parts being interchangable would you guys go with a 351w long or short block?

3. I am in Arlington Virginia, any suggestions on where to be either blocks?

4. I do not have a shop so I do all work in my living room.....lol I have also rebuilt an engine before however I had many more resources this will also play a part.

 

[mcdobson]

If it has original 302 heads, they will not bolt to the 351w. 302= 7/16" bolts
351w = 1/2".

You can stroke your 302 (331,347 etc..), get the horse power and torque and no hassles of converting to 351w. Like hood clearance, firewall clearance, accessory brackets etc..

 

[duganfife]

true..

but from what i can find online a 302 stroker kit alone will run me around $800 not including labor and other costs.....351w long block for around $1300-$1500?

 

[TBS-POPS]

Build a stroker from your 302, it will run better with less hassels as someone else stated...

 

[recoiljunky]

No replacement for displacement. I wouldn't waste my money building a 302 when you could build a 351W for the same $. It may be a little more trouble fitting the 351 but it is definitely worth it.

And then stroke the 351.

 

[deltarat]

You can get the same HP and low end torque as a 351 with a stroker?

 

[Bronco Brian]

No replacement for displacement. I wouldn't waste my money building a 302 when you could build a 351W for the same $. It may be a little more trouble fitting the 351 but it is definitely worth it.

And then stroke the 351.

X 2 I have a 5.0 and looking for 5.8

 

[broncnaz]

While I can't argue with no replacement for displacement. A stock 351W would be a good reliable engine with more useable powr than a stroker 302 and cheaper. But rebuilding or getting a long block 302 will be the cheaper route while many parts do interchange between the 302 and 351 you will still need a oil pan and pickup and accessory brakets or adapters to adapt the 302 brackets to the 351 then theres always odds and ends that are needed that may drive the cost up.
If your 302 truely has only 80,000 miles on it why the rebuild? I would really consider maybe a cam/lifter swap, new timing chain, oil pump possibly rod and main bearings and thats about it on a 80,000 mile engine. This can really wake up the mid 70's 302's Maybe a set of rebuilt heads also. If the engine is tired you may as well consder the tranny tired. I would also consider getting the tranny rebuilt theres not much sense in building a engine only to have the tranny go south on you. Especailly if you go the 351 route as you will be putting out more torque which is more strain on the tranny.

 

[trailbound]

i agree with broncnaz. Just to a macco rebuild i.e. break it down to a short block, have the heads fresh'n or just pick up a set of better used heads (last yr i picked up a set of gt40p heads w/roller rockers and gt40p stainless shorties for 500 shipped. you just got to keep your eyes open and hit the mustang sites) throw a nice cam in it, put it back together and run.

minus buying a set of heads you should be able to do this for under $500 and the motor should be alot more lively. Not to mention when its stripped down to a short block you can check cylinder walls and such and determine whether or not its time for just a new motor.

last but not least, check out howell performance.
http://howellefi.com/customer/home.php
Its a stand alone TBI. much less complicated then ford efi, and since its the same size as a carb there is no fitment issues under the stock bronco hood.

 

[trailbound]

oh i forgot, if you found a good deal on a 351w short block, you can have the head bolt holes in your 302 heads drilled out for $50. that way you can use them on a 351.

 

[Broncobowsher]

A stroker 302 comes in at 347, still smaller then the 351.
Think of this, if stroking the 302 was so simple why did Ford do all the work to make the 351W? The answer is the 302 isn't up to the task of good durability when stroked. Rod angels suck, wrist pins are in the oil rings. A standard 351W has rods over half an inch longer then the 347 rods. Long rods are good, just ask and chevy builder how much they like it when they get to step up from the 5.7 rod to a 6.00" rod. Then there are all the little things, larger head bolts, larger main bolts, larger bearings throughout, even a larger oil pump driveshaft.

I have never seen a 347 built with 9:1 compression, stock cam and a set of stock heads, but they always compare there built 347, saying how much power it makes (with a good cam and heads, usually with a good deal of compression as well) to stock 302 and 351W engines. If you ever find a real comparison that shows a 302, 347 and 351 all built the same the 351 will do best (unless the parts are specifically picked to go against the 351)

 

[mcdobson]

Yes the 351w always has more possibilities than the 302 (even stroked).
But the OP says he has a couple grand, and limited ability but wants improvement. Upgrading the stock 302 is probably his best bet but having a machine shop build a stroker that bolts up to everything without a hassle outweighs the advantages of the 351w for this guy IMO.

 

[needabronco]

If you've only got a 'couple grand' you'll be miles ahead to just rebuild the engine you have.

Any stroker that would last more than 30k miles will cost you more than you can afford.

A stock rebuild will push your budget anyway... I'd do a mild cam, matching intake upgrade, new carb, and if you can an exhaust upgrade, and leave it at that.

 

[mcdobson]

You can build a stroker that only lasts 30K?

 

[needabronco]

I was simply stating that 347 strokers are not known for lasting 100k miles, they usually only live a fraction of that. 302's and 351's last 200k or more if they are built right and taken care of.

 

[mcdobson]

The key words there for any engine are built right and taken care of.