[jesusm3]

I got offered a short block from a 1998 mark viii for $250. I am planning on building a drag car for my daughter and so when she gets old enough that is something we can do together. I plan on goimg with a fox. I have a dd fox so I am not new to them, but I am new to the 4.6. If you can give me any input it will be greatly appreciated

[zinc-vert02]

for a fox i would build a 302 or 351, probly cheaper and easier to fit in the fox

o and less weight

[jesusm3]

Ive been doing reasearch and come to find out it seems to be cheaper to build a 4.6 than a 5.0.

[bitemark46]

Mark 8 shortblock= Teksid block (keep it). The rods and crank are the same junk they put in the 96-01 n/a cobras so if you plan to upgrade do h-beams and a quality piston. The crank is cast (same ast the gt's).

[NeverEnuff]

If the shortblock is good. Go cheap.

PI heads (net you 11:1+comp)
PI cams or aftermarket
Edelbrock intake
6061 elbow
75mm throttle body
Longtubes

Right there is a 330+rwhp combo...get some ported (livernois CNC'd) heads, and it will clear well over that mark. That would be plenty fast for most...

[jesusm3]

Are thr stock b heads worth keeping?.

[jesusm3]

Keeo in mibd this will be 90% drag car

[NeverEnuff]

Depends...Mark heads are just a bit inferior then the cobra heads. But still flow.

If you plan on stayin NA...um...prob not. It won't make good power unless you cam it, spin it and put some compression in it...

[jesusm3]

How cheap would you go?

[majorownage]

Originally Posted by NeverEnuff Depends...Mark heads are just a bit inferior then the cobra heads. But still flow. If you plan on stayin NA...um...prob not. It won't make good power unless you cam it, spin it and put some compression in it...

what are you talking about? they are exactly the same head

4v>2v

[bitemark46]

There is a small difference in the bowls but probably not noticeable on a dyno.. Big difference is the cams. Mark 8 cams are less agressive compared to 96-98 intake cams. Full bolt-on B-headed cobras can make 320-330rwhp.

[NeverEnuff]

Originally Posted by majorownage what are you talking about? they are exactly the same head 4v>2v

Lol. Majorownage is correct for your name.

Thanks Mark.

You will prob see a diff in the dyno. Maybe no where else. The bowls come in and surround the valves...Cobra heads do not do that.

[majorownage]

Originally Posted by NeverEnuff Lol. Majorownage is correct for your name. Thanks Mark. You will prob see a diff in the dyno. Maybe no where else. The bowls come in and surround the valves...Cobra heads do not do that.

maybe on older mark viii heads...


I have a set of 98 mark viii heads in my garage and a set of 98 cobra heads.

They are exactly the same....except of the cams of course.

[NeverEnuff]

Every Mark head I have seen has this. If you got a set that don't. Check the casting number.

[mfj]

Originally Posted by jesusm3 Ive been doing reasearch and come to find out it seems to be cheaper to build a 4.6 than a 5.0.

I don't know what you consider "research" but you are WRONG. It is so much cheaper to build a pushrod motor than a quad cam mod motor.

[NeverEnuff]

^ Um. Not if you do it right. Most bolt on HCI 5.0s I seen barely clear 300rwhp. Put a fresh 306 in it and up the compression just a tad and you MIGHT get 330rwhp. I know cause ive done it.

A stock lincoln aviator motor can be had for 1500, add cams at 990, longtubes and a tune. Thats 350-380rwhp depending on the cams and intake...Um...most good 5.0 heads are 1200+...mind you...the 4v is a stock longblock with cams making more power than 5.0s with HCI...

[NeverEnuff]

Bueller....Bueller...???..anyone...

Where you at MFJ???

Funny part is...you drive a 4 cam. lol.

[mfj]

Originally Posted by NeverEnuff Bueller....Bueller...???..anyone... Where you at MFJ??? Funny part is...you drive a 4 cam. lol.

You completely missed my point. In terms of absolute cost, building a pushrod motor is MUCH cheaper than building a 4v. It's not up to negotiation. That's just how it is. And if you are not paying for labor, the amount of "sweat equity" you will have in your 4v is much more than a pushrod motor.

And yes I drive a 4v. If I had to do it all over again, I would have done a built LQ9 GM pushrod engine and a couple of snails, and still wouldn't have spent even close to what I did on my current set up.

The heads and OHC is what makes everything so much more expensive. 4 cams instead of one. 4 times the valve springs. I think you get where I'm headed with this. Valves, retainers, etc...

[DickH]

I really want to vote for the mod motor being better money spent if you want a chunk of hp but I have not sat and priced anything. 4v heads and cams could be left alone if the cost of dealing with 4 cams and 32 valves is really a big deal. Plenty of 03-04 cobras seem to be doing just fine with what ford gave them. I think that by what it takes to make decent hp, price shouldn't be an issue and you should just do whatever you would enjoy most. Stock mod rods break ~450, and that could just as easily be the case with a 302 block. I guess FI is FI and its probably going to cost about the same for either so you are stuck with block, rotating assembly, heads, cam and intake for the 302 vs rotating assembly and maybe cams for the more expensive 4v 4.6.

[mfj]

Well yeah. In the specific case of Ford, they jewed their customers with a shitty block back in the days of the 5.0 Foxes. Dart blocks can handle anything but are expensive as shit. GM got it right with their LSx engines which are still, to this day, the best bang for the buck you can get for hp. And much easier and cheaper to build than a Ford Mod motor.