Stupid engine newb questions (cams and carbs)

[03rangerxlt]

I have never done anything to the guts of a motor, and this is my first carb'ed vehicle. Someone suggested a cam and upgrading to a 4 barrel carb would wake my 351M up a little. Can I just buy an appropriate cam and just get my mechanic to install it? Or is it not that simple and its gonna require more upgrades in the motor? What cam do I order? I looked on the Crane Cams website and saw there are cams for the 351M for a lot of specific purposes. What 4 barrel will work with my 351M also? Wow I am such a newb.

[DGrant09]

Those are actually good questions! And ones that I cannot really help with.. Not long ago I was asking the same. The folks around here will chime in soon with help but they may want to know what you want to achieve with the engine, current setup (stock, headers, etc..) and the condition (compression, etc..).
As for mine, I soon found that it was best to rebuild the complete motor. I'd fix or improve one item and then due to age and the increase in performance an older component would fail.

[Jake11]

I would do a leakdown test first to see if its worth messin with. Jake

[DuckRyder]

Assuming that the engine is otherwise in good condition, a cam and four barrel might very well wake it up. Headers might be an excellent idea as well.
I do not know specifics on the 351m but generally:

It is not a good idea to use a new can with old springs, since the lift is higher the stock springs may coil bind and cause damage to the cam and valve train. Unless you have the equipment to test them, it will probably cost as much to test stock springs as to buy new ones. On a flat tappet cam, you must replace the lifters as well as the cam.

I would say the most common mistake in cam selection is to pick too large of a cam, to “wake up” the engine you are looking for increased low-end torque. That means mild cam timing. Fords generally like a dual pattern cam, meaning that the exhaust has more duration than the intake by 8-12 degrees. Crane, Crower and Lunati are all excellent cam grinders.

Pick a dual plane high-rise manifold.

You’ll get a “Chevy – Ford” argument about carburetors, but on a 351 sized engine I would go with a Holley 670 street avenger for a big heavy truck with an automatic, definitely a vacuum secondary and no bigger than 750CFM.

Considering your admitted inexperience this might be one instance where one of Edelbrock’s “power packages” would be a good choice. I am not a fan of Edelbrock, but these packages do take the guesswork out.

You can at least use it as a guide to select similar components from other companies.

Me, I would probably go with:

Weiand Action Plus Part #: 8010 intake

Crane 523942 cam and lifter kit

Holley Street Avenger 670 Part #: 0-80670

Hope this helps.

[03rangerxlt]

Hey guys. I appreciate the replies. I think I will talk this over with my mechanic on Monday when I see him. Duck, I see your in the ATL area. Very cool. I am in Marietta.

[My427stang]

We did a 351M for a customer in a SB 4x4 F-150. It was very mild but ran VERY good.

Our setup was basically intended to be a stock rebuild, but adding a 4 barrel and good exhaust, and a very mild cam to pass MA emissions at the time

We did an entirely stock rebuild, except for
- Edelbrock Performer Cam 204/214 duration @ .050, and matching valve springs. (Be sure to have him degree it, some timing sets put the cam late and that kills torque/vacuum)
- Edelbrock Performer intake
- 600 Holley vacuum secondary carb (Edelbrock would work just as nice)
- Headers and 2.5 inch duals

You would not believe how that truck woke up. It wasnt a drag car, but it felt like it gained 100 hp. The owner, who used it for a work truck in a carpentry business got us more referrals than we ever got with a higher hp motor. It was a very nice combo.

The only think I'd do differently today (this was probably 14 yrs ago) is that I would zero deck the block and recurve the distributor, but those would be minor gains. That was a very nice combo