351 EFI w/ Explorer serp dress and 4R70W

[chuzie]

I am looking at doing an EFI 351 w/ an Explorer front end and 4R70W transmission.

Since I am already running a 302HO EFI w/ Explorer front end and 4R70W, I want to reuse as much as I can during this swap.

I was going to upgrade my existing Mustang intake with Explorer upper and lower but I guess that is no longer feasible with the 351 unless I want to track down a Lightning (GT40) lower to mate to the Explorer upper. I will go the BC Broncos adapter route and find a 351 EFI truck lower to mate to my Mustang upper.

My 351 is currently carb and the block is a '79, so rollers are not in my immediate future without a cam swap and some work. Correct?

What is the deal with the 5.0 Distributor on the 351? I have read it needs to be longer so grab a EFI dizzy off a 351 EFI truck. True?

Also thought I read somewhere that the AC/PS bracket is not compatible to the 351 but not sure if that is the Mustang or Explorer bracket. Not sure. Didn't see mention of that in the Explorer Serp write-up in the tech section.

Came across something that mentions a 94/95 balancer could be used with the Explorer setup but that makes zero sense. Thoughts?

I know I can either rebalance my Explorer balancer with damperdudes or use a Bronco balancer with the Drivenautoparts pulley.

One dilemma I have is my flexplate. Just bought a brand new 50oz flexplate for my 4R70W a few weeks ago for another problem I was working. I suppose I can have it rebalanced, but I also have a 28oz 164 tooth flexplate that is already on the 351 and was bolted to a C4. Is this flexplate compatible with the 4R70W? I know there are issues with backspacing (3/4" vs 1/2") but not sure if that is using an AOD flexplate with a C4 or a C4 flexplate with an AOD.

Does anyone see the need to do a shift kit for the 4R70W with the 351 upgrade?

 

[hmh800]

I've put a 351 efi in my project, with mustang efi. I did use a lightning lower, but the truck lower would work too (bummer, sold mine for scrap). You do need a 351 dizzy as the shaft is longer. I used the one from the truck motor (remote TFI) and reworked the wiring harness as needed. If you're not using a roller cam, I guess you'd need to find a dizzy off an earlier 351 to get the right gear. Brackets for all front dress will work with the 351. There may be one bolt that doesn't line up. Don't remember, but it works. Hope this helps!

 

[chuzie]

Thanks for the info. I think the bolt you are referring to is on the ALT bracket; no biggie.

 

[Viperwolf1]

Explorer brackets will fit even better on a 351W than on a 302 in a Bronco. The alt bracket/lower idler pulley gets pulled up enough to clear the crossmember. The '94-'95 mustang balancer/pulley won't work without some work, might not work at all. Use the explorer balancer (rebalance) or get the Driven Auto pulley. Don't waste time/money rebalancing a flexplate. New ones are less than $40. C4 and AOD/4R70W flexplate are the same size (164 tooth) and offset. C6 uses different offset.

 

[blazinchuck]

viper...the 28oz flex plate thats on the 351/c4 set up wont work?

 

[chuzie]

Chuck, I think he was just saying rebalancing flexplate was not cost effective.

So I will reuse the C4 flexplate currently on the 351, and

Utilize all my existing Explorer serp stuff.

Snag a 351 EFI lower,

Find a 351 EFI dizzy for a non-roller,

Do a pulley or rebalance the explorer balancer,


Now, just gotta determine if I need a shift kit for the 4R70W and if making this sucker a roller is worth my while.

Thanks for the quick responses.

 

[Viperwolf1]

viper...the 28oz flex plate thats on the 351/c4 set up wont work?

It will if it really is a C4 flexplate and not a C6.

 

[chuzie]

Ohhhhh. So we need to make sure we CORRECTLY identify this flex plate C4/C6. Suggestions?

Is there are know measurement we can take from the back of the block to the plate?

 

[blazinchuck]

gotcha...as for roller/non roller...the only thing id be concerned with is the cam in this 351...PO can not recall what cam it was(mild or wild)-its not stock.

guys...is there a way to identify a cam if its pulled out?

 

[broncosbybart]

I think viper is getting at the bolt locations for the torque converter on the flexplate, not a difference in mounting depth or anything.

I think I have a 351 truck lower still, if you want it, I'll trade you for that problematic 4 link in the rear

Yes, a 351 dizzy is different than a 302. You'll need one of those.

This intake I have is yours, if you want it.

Edit:

The cam should have some info stamped on it that you can reference. I guess you are using that old 351 you just pulled? Any idea on how it ran, or are you going through it?

 

[chuzie]

Found it here, see info below...

"The 1000 words... The plate on the left is the C4/AOD/4R70W offset. The plate on the right is C6/E4OD offset. If you look right where the ring gear meets the plate, you'll see how the C4 plate steps down(towards the crank), and the C6 plate kinda steps back up towards the trans."

Chuck, I don't think we can use the 302 roller cam in the 351.

 

[Viperwolf1]

Ohhhhh. So we need to make sure we CORRECTLY identify this flex plate C4/C6. Suggestions?

Is there are know measurement we can take from the back of the block to the plate?

I have a couple C4 plates. I can measure the thickness from the crank surface to the teeth edge. I don't have a C6 plate to measure.

The reason I mentioned it is there were not many C4s originally fitted to a 351W.

If in doubt just buy a $40 flexplate.

 

[broncosbybart]

Nah, that roller cam won't work in a non-roller block. I'm guessing that is what that old thing is.

 

[blazinchuck]

i know moody has mentioned it before...and said slap a roller cam conversion and run the mustang cam from yours or mine. so im pretty sure 302 cams work

 

[broncosbybart]

if it was converted/modified, the cam should work. firing order is the same on the 50 oz 302 and the 351's.

 

[chuzie]

Browsing a thread @ corral.net I came across some great info about the swap.

Basically, with my 79 block to have my 5.0 HO roller lifters, I would need a "Small Base Circle Cam." It also said

"NOTE: Small Base Circle Cams are known to be less than ideal, as they are weaker. There are not as many cam profiles available for the Small Base Circle Cams, so your Off the Shelf Cam selection will be severely limited. If possible, it is recommended to avoid the Small Base Circle Cams.

First the spider will require 2 holes to be drilled in the main valley. These holes will be drilled over the cam bearings, so great care should be taken not to damage the camshaft or bearings. Risk can be minimized by removing the camshaft, and drilling the holes before the cam bearings are installed. Some grinding may need to be done to allow the factory 302 dogbones to sit flush on the 351w block as well. A Dremel is adequate to get the job done. Be patient and work slow; it is easier to remove material than put it back. Of course it would be best to do this work before having the block cleaned and prepped for assembly. Ford Hydraulic Roller lifter (for both the 302 and 351w) part number is M-6500-302."

Bart, thanks. I may hit you up in a few days for that lower intake.

Viper, I would certainly appreciate that flexplate measurement just as a precaution. Wanna do this right the first time.

 

[Viperwolf1]

Viper, I would certainly appreciate that flexplate measurement just as a precaution. Wanna do this right the first time.

Here are the measurements on the common 164 tooth C4 flexplate. The oddball 10.5" bolt pattern one is a little different where the bolt holes are.

 

[chuzie]

Other option would be to pick up a set of crane # 36532 or eq. and use the stock HO cam. New they are about $600 or used around $300.

For now, I think I will leave well enough alone. This is a budget swap.

 

[chuzie]

Thanks Viperwolf.

Chuck, when you have a sec, you think you can run out and take a pic of the flexplate on the 351 and duplicate the measurements done above?

 

[blazinchuck]

Thanks Viperwolf.

Chuck, when you have a sec, you think you can run out and take a pic of the flexplate on the 351 and duplicate the measurements done above?

yep yep...but after work today