I've been lurking here to learn a little about how you guys are getting powerout of these. I'm starting with a 76 4V motor. I'll have the heads apart for some re-seating and 3 angle valve job so I'll do a lil bowl work and thin the stems but no port enlargement. From what I gather here the trick is to use the 360 rebuild kit. I'll upgrade to the RV cam and find a used dual plane and headers.

Should I deck the heads to get rid of some of the recess?

Will this combo get me over 300hp reliably?

 

If you deck the heads the intake will need decking too. And the push rods...

Might be cheaper to get a set of car pistons, check it out but as I appreciate it they are .1" taller.

puttster

 

My opinion is to scratch the rv cam and go with something a little more agressive, rv cams suck with higher compression like that 4v motor, you'll get more power and better mileage.

 

Joedaddy, How are you going to use the engine? If you have a 76 4V engine, it is a 390 already. Adding a little cam & headers will make it pull better.

If you are wanting high rpms you will want to go in a different direction.



John

 

Not always true. Intake fit should be checked after a head mill and before milling the intake. I've had two motors with milled heads that needed no intake mill to amke em fit.

 

The only gotcha is that the cork end gaskets can be thrown in the garbage

As for a 390 with some "grunt", the original poster is on the right track.

An "rv" cam is a toss-up though - post what cams you're looking at and these guys will pick 'em apart

 

Hence the reason to go with a 360 kit. The 360 uses the .100 higher CD pistons that were originally 390 pistons. This combo nets 9.3-9.5:1 CR with the later model heads.



As for the OP looking for a good used dual plane intake, the factory iron manifold will work just fine up to around 5500 RPM. Save your money, unless you happen across a killer deal. That money could be used for other stuff that would have a much better end result, like headers or better cam/lifters/timing set.
Granted, the iron manifold weighs about 45-50 Lbs more than an aluminum one, but how often do you plan to pick it up?

 

So the factory 4V intake is good?

The engine will live at around 2000-2200 rpms. It will have an occasion to see a muddy field or 3 so 6000 rpms is not out of the question.


It will have headers and thrush (used to walker/dynomax) 2 1/2" Turbo muffs.

 

Here's my combo -- standard bore 390 (was a 2V out of a car) rering kit only with the following mods:

Edelbrock 1404, 500CFM:
Jets, .086/.098
Nozzle, .28, bottom hole on adjuster
Springs, Pink
Metering Rods, 65x47
Performer Intake
2 1/2" x 14" Air Cleaner

Hyd. Flat Tappet Cam (Melling MTF-4):
204/214 @ .050
.486/.512 Lift
104/120 Lobe Ctr.
107 Lobe Sep.
Comp 940 valve springs

Hedman Headers
Dual 2 1/2" Exhaust with Crossover, Behind Tire Exit
Walker SoundFX Mufflers

OEM 1974 Breakerless Electronic Ignition
11 Degrees Initial, 36 Degrees Total Timing
Autolite 45 .036 Gap

C6 Auto
Stock Converter
3.00:1 Gear
31" Tire

Nothing done to the heads (C8AE-H) other than lapping the valves with an electric drill, they already had hardened exhaust seats. I tow 4000lbs 400mi. to the drag races in Topeka a couple times a month with it in my 68F100 and get 10mpg at 65mph/2100rpm. I can get 14 on the highway without the trailer at 60. The truck just walks up some pretty good hills, even with last week's 40mph headwinds (took my mileage down to just under 9).

 

I overhauled the 4 bbl 10 to 1 390 in my 68 Merc with a Crane 272* Energizer, left the C8AE-H heads as is, topped it with a 428PI intake, 3310 750 Holley and went with FPA headers. This combo would burn 89 octane fuel, idle had just a hint of a lope when cold, pulled from idle to 5500 rpms. The big Merc (4200 lbs) ran 14 flat @98 in the 1/4 with a 3.70 geared open diff 9" thru the stock C-6. I had a identical build in a 70 F100 in the 80's but with a 296* .516 lift cam (Cam Dynamics) and would run on 87 and run the 1/4 in 15's with a 3.50 rear.

 

Is there a specific Head gasket y'all recomend to get rid of some of the open chamber, or just go with the thick fel-pros?

 

I used the Fel Pro Permatorque Blues. Stay away from the Print O Seal (P.O.S.) I also liberally coat my head gaskets with Copper Coat before using them just as extra insurance.