351W Stock Rebuild Now, 408 Stroker Later

[ElMustachio]

Hey everyone. I'm new here seeking any advice you folks are willing to give.

My wife sent the inline 6 cylinder in my '67 to engine heaven during a trip to work earlier this summer, so it pulled my timetable forward on the engine swap I had planned. I've got my hands on a roller 351w out of a '96 F250 that was still running at the time the truck was wrecked. Long term (say 5 years down the road) I would like to do a full tear down and have myself a moderate 408 stroker, but for now I want to more or less convert the motor over to a carb and run it as is. I've got a 2" body lift and have a ZF5 tranny to take into account when it comes to clearance/fit up.

As I look to buy an intake manifold, carb, and headers I am trying to find something that will work now with the stock motor/heads and something that would work long term after my full tear down. Is that crazy? It seems like a Weiand Stealth intake manafold and some shorty headers (either bc broncos or bronco hut) are talked about for install on a stock 351w, and it seems they would interface with a tfh twisted wedge 170 head that I could go to during my stroker build. I've seen a lot of folks recommend the afr 185 heads, but I don't think they will interface with an intake or headers that would work for my stock setup. I've also seen the bronco hut headers suggested due to the 3" primaries. I don't anticipate that would matter much for my stock build, but if it will affect things down the road I don't want to be short sighted. Finally, I'm figuring on a 750 cfm dual pump Holly carb that would probably be more than I need with the stock 351w, but that I've seen touted for a 408. With the right adjustment could the carb work for both setups? I probably will need to worry if the stack up will all fit under the stock hood, no?

I realize the easiest thing would probably just to bite the bullet and do the full build now, but like everyone else it comes down to dollars and having the sense to not spend too much from momma's check book. I'm just trying to find a middle ground, so I don't end up having to buy parts twice.

Any advice is much appreciated!

 

[DirtDonk]

It's doable. But maybe saving a little more while you're running this 351 for the next few years so you can just buy another new block would be good too.
That way you can keep driving your setup while you fully build your dream engine.
Not that you can't do it either way, just that it might let you have more fun for a little extra dough.

And extra dough is what you're going to be spending on a few things.
The heads, headers and intake are probably fine to run on both engines, but I personally would not run the 750dp on a stock 351 even if I tried to tune it down for use later.
Just buy the right carb for stock, then when it comes time several years from now, buy a new carb more appropriate for the big motor. What kind of cam and hp numbers are you looking to squeeze out of the big motor down the road?
That cam choice may be the biggest deciding factory in what parts you re-use.

Paul

 

[nvrstuk]

ElMust....

I've been down this road...here's what I would do and it seems like you're trying to do the same- use lots of parts for both builds.

170 heads are TOO small...waaay to small for a 408. Don't even think it... You will NOT lose torque by going to a larger cc head !

Holley 750 is way TOO big for your 351W.

My suggestion:

AFR or TrickFLow 185 heads. 351W won't use all of it but the 408 will AND could use more.

Holley 750 will literally drown your 351W even if you try smaller jets. Go Quadrajet...here's why. The qjet can be easily tuned, yes very easily tuned to operate perfectly on a 4 cyl and on 500 cubic inch Cadilac engines. Yes- very well in fact. No gas smell, not running rich...but as perfect as a carb can be. The qjet is as close as you can get to a variable venturi carb. I have rebuilt several for 4 cyl marine engines putting out 175hp and I have rebuilt dozens for 302, 351W's, 408's, 418's, etc.... putting out over 500HP, they really can do it all. Ask around a 4x4 forum and guys that actually know something about carbs will readily agree. Look at the primaries on a qjet...instant air flow and throttle response. You will notice the difference!

So, 185 cc heads (either AFR or TF), mount not a Stealth but an Edelbrock Performer Air Gap intake. https://www.edelbrock.com/rpm-air-gap-intake-manifold-7581.html This manifold likes the stock 351W just fine and when you bump up to the 408 you won't be choking it. You will need an adapter for the qjet. Go with a drop style 14" filter and a Mustang II, 302 cube air filter element to keep it as low as you can.

Ports match up great to the TrickFlow heads, flows great numbers with the 185 cc heads, air gap helps with heat sink issues and it flows remarkable even.

This combo will allow the best of both worlds. I've done this 351W to 418 step and this combo worked great.

Headers- the BroncoHut headers and BC's both use 1 5/8" primaries. BH has 3" collectors instead of 2 1/2" from BC. Can't go wrong not restricting flow here. Long tubes aren't what you asked about so I didn't comment on them. I can't run them as they seem to attract rocks .

You will have to purchase two cams. Way too much difference in air flow to be able to get the best of both worlds out of one cam with over 50cubes difference in size.

IF you buy a store bought cam (I am not a proponet) then talk to at least THREE different sales guys from EACH company. You will be blown away how each sales representative recommends a different camshaft...quite a bit different.

Otherwise, for your stroker- talk to a builder of strokers who deals with JUST Ford strokers or does so many SBF strokers he can recommend a cam in his sleep.

Jim at Fordstrokers.com is just the guy. He builds mild to wild and ALL he does is build Ford stroker motors. Or for custom try Ed at flowtechinduction.com he's always done right be me. Great guy- knows what the heck he's talking about!

Best of luck on your build...do you have a body lift?

Hope this helps some...

 

[nvrstuk]

WOW, just noticed this was your 1st post...welcome aboard!!

 

[ElMustachio]

Thanks for the info guys and thanks for the welcome. I've lurked on here gleaning information for two years and figured I might as well join in on the fun.

This advice is just what I was looking for.

For the heads I am planning on just leaving the stock ones on for now. Then during my rebuild I'll for sure look at something a little bigger (185 AFRs or 190 TF). Will the AFR heads mate up with the intake you suggested and the headers? I have seen posts with people talking about having to do grinding and fitting on their brand new ceramic headers to get them to work and that makes me cringe.

I had a suspicion the 750 carb would be way to big, but figured it didn't hurt to ask. Last night I found a 670 Truck Avenger carb only slightly used for $135. I don't do a ton of extreme wheeling, but I've seen quite a few folk on here with good things to say about them. And I figure that can keep me from having to adapt to the intake. Still not sure if it can be jetted down for my stock motor, but I can find a cheap stop gap if need be.

Just like the heads I am probably going to leave the stock cam in for the time being. I will definitely be getting in touch with the guys you suggested for the cams for my rebuild. The amount I know about cams at this point couldn't fill a thimble and it seems like there about a million options. I am just looking for something that will run on pump gas, make somewhere between 375 and 425 hp, and have plenty of fun low end torque.

Thanks again for the input.

 

[Broncobowsher]

Don't have much for the stock motor. Make sure you have the right distributor gear material for the cam you use. That is the big one. If the plans are to rebuild it later, put as little into it now as possible. And what you do put in, make it usable for later. Even if not ideal for now.

As for the stroker, years ago I started a thread "20 questions for stroker owners". Tons of good info in there. Made a requirement that you couldn't respond until you drove it for a year. Just to get real answers, not just "it runs and anything that is running is great" answers, work through the issues and what resolved them. That kind of stuff. Go search for that thread, have a good read.

 

[Timmy390]

The 96 roller will run well. It has the explorer cam in it which works well with the Bronco. The E7 heads are not bad for a stock engine. Stock should be 210HP and 328 torque.

I ran a 96 E350 roller engine rebuilt bored 20 over for a few months. Ran very well. Turned out I had a cracked head so I upgraded to GT40P's and did a cam swap. Runs very very well now....

If the motor runs and has no leaks, drop it in and throw an explorer front dress on it and go....rebuild later as per your plan later.....Grab the Explorer exhaust manifolds too and save up for the headers vs buying them now......

Tim