I have a 305 with a summit cam that has intake 204@.050, exhaust 214@.050 and .420/442 lift with 112 Lobe Separation. The motor has a edelbrock performer intake with a holley 600 vacuum secondary on it. It has 1 5/8" headers going through dual 2 1/2" exhaust. The tranny is a th350 with a 2200rpm stall and 3.36 gears/posi with 25" tires outback. I am going to put ported #416 heads with 1.84 valves on it to raise the compression slightly over the 60cc-1.72 intake valves stockers. My question is, should I upgrade to a bigger cam? This is in a 3700lbs car. Any guesses on what power it will make. Thanks for the help.

 

This looks like a great site.

 

That gear ratio doesn't make any sense, is that a typo?

416 heads didn't have 1.72" valves stock, they *should* have 1.84"s stock, and the common upgrade is 1.94. I'd go up to that one. They are also nominally 58ccs, so if they're 60, then you've already lost compression there.

mwnova66 ran that cam in a 305, IIRC, he did quite well with it.

3700lbs?!?! Good god, what kind of car is this?

What usage does the car see? Are we talking about dragstrip results, or daily driving, just adding a bit of oomph?

Either way, I would upgrade to a bigger/better cam, yes. Might need more stall if you go much more though.

 

Sorry to confuse you with my post. I was stating that I am putting ported 416 heads on it that have 1.84 valves in them. They will be REPLACING the stock heads that have 1.72 valves in them. The new heads will have 58cc chambers and the old had 60cc, so I will gain a little compression, A little over 9:1. This is just a weekend cruiser I sometimes drive to work(5 miles). The gears are not a typo, they are 3.36, they act numerically higher because of my short tires. Thanks for the reply. Should I stick with the cam or switch it.

 

It's really weenie; like, less than some stock cams. But that doesn't necessarilymean it needs replaced.

Clearly this is not a 3rd gen.

How much does this truck weigh? How does it run now?

 

It weighs around 3600-3700 lbs. It runs okay, great power from 2000 up to about 4500. Then it just seems to run out of power, like the heads arn't keeping up. It can spin em from a dead stop no problem, break the tires loose shifting into second. I just wondered with the new better heads if I should up the cam.

 

2WD no air? 70-72 more or less?

 

I would say that it is a C20 with like a 14 bolt because of the 3.36 gears.

2wd to be that light.

The 204/214 cams give up around 4,200-4,500 rpm in a 305. They will spin to 6,000, but the power is gone well before 5,000 rpm.

MW ran the next step up at 214/224.

I liked the Comp Cams Extreme energy 274 that I had in my 305 in my Van. Very strong pull from 1,800-6,000+.

 

Exactly, that weenie cam is done by 4500 RPM or so. an xe274 would slaughter the low end in a truck that big and heavy with the moderate gears in it and low stall, IMHO. To really move a truck you need more than 305 cubes, you're just in the wrong ballpark. Like a V6 in a 3rd gen...

But, working with what you've got, an xe262 would help it out, 218/224 IIRC.

ah, ok, 3.36 ratio didn't make any sense to me at all, but hey, i'm wearing my 3rd gen blinders so...

 

The 274 didn't slaughter my torque in my VAN. 3.08 gears and a 700r4 with a 2,000 rpm converter.

NAH, that truck is still going to be turning around 2,500-2,700 rpm doing 70 mph down the road. Peak torque will be about 3,000-3,500 with a XE274 in a 305. Peak HP will happen about 5,500-6,000 rpm. He will be under 1,500 rpm at basically idle only.

XE262 is TOO SMALL for a truck that lacks overdrive.

305s can make very strong low-mid range torque.




This is my last 305 build.

423 Flywheel Horsepower @ 6,500 RPM. I have not had the engine in a car yet with this combo, but I bet it would do low 12s in a 3rd gen with traction.

Block = 1983 4-Bolt main 305 (14010203 casting), Bored .040" over, Torque plate honed, Decked .025", ARP Main Studs, Align Bored

Crank = Stock GM Forged Steel (3941188), Lightened, Smoothed, Knive Edged, etc for less windage, balanced with the entire rotating assembly

Bearings = Federal Mogul Speed Pro Coated

Rods = X casting rods, Parting lines ground down, Lightened, Balanced, Shot Peened, Weights Matched, ARP Wave Loc 3/8 Rod Bolts, Reconditioned

Pistons = Stock L69 Hypereutetic Replacements, Flattops with 4 valve reliefs, -6 cc, 0.00" in the hole

Rings - Total Seal Gapless rings

Compression = 10.7:1 with 54cc heads, Zero Decked block, .038" compressed head gasket.

Heads - Ported 2004 ZZ4 castings ("463"s), cleaned up in my garage, final "MAX EFFORT" port work performed by my buddy in his machine shop, .100" longer valves than stock (1.94/1.55 Under Cut Stems, Swirl polished), 5 angle valve job, Forget the exact spring but they are meant for the cam and .100" longer than stock valves, .600 lift compatible. I had to use longer than stock push rods as well. Machined heads for Comp Cams guide plates after opening up pushrod holes in heads. Gasket matched to a Felpro 1206 (1.34" x 2.21")

Head flow @ 28 in/h20 with a 3.75" bore simulator (engine has 3.776" bore).
Lift------Intake---Exhaust
.100------57-------57
.200------123------118
.300------177------162
.400------223------183
.500------229------188
.600------238------193

Camshaft = Comp retrofit roller XFI280-H13 (280/288 @ .006, 230/233 @ .050, .576/.570" lift with 1.6:1 rocker, 113 LSA, 106 ICL) Cloyes Double roller timing set

Intake Manifold = Holley Projection TBI for "OLD" style heads with the same bolt angle. This intake is a dual plane, high rise, with 2" bores. Gasket matched to the Felpro 1206 intake gasket

TBI = TBI unit off of a Heavy Duty 7.0 liter TBI truck, 68# injectors at 32 PSI, 2" bores, thinned throttle shafts, radiused the entrance to the bores, sitting on a 1" tall open center TBI spacer, 720 CFM @ 3.00 in/hg

Headers/Exhaust = Hooker Super Comp 1 3/4" x 3.5" meant for a mid 70s Camaro with a 350. 3" duals with X-pipe (not used on dyno)

Ignition = Stock GM HEI EST small cap distributer (computer controlled) with MSD coil, MSD Module, Moroso Ultra 40 wires, AC Delco Rapidfires @ .045"

Oil System = Moroso Blue Printed Oil Pump w/ Pickup, Moroso Steel Shaft, Moroso 5 quart pan, Moroso Oil Control Kit, Mobil 1 5w20, 70 PSI Z/28 spring

Crankcase Evac = LT1 style Electric AIR pump pulling a crankcase vacuum of about 6 in/hg.

ECM = RBob's EBL with lots of tuning. 34* total advance @ 2,800 rpm.

Dyno Numbers (all rounded to the nearest whole number for simplicity)

RPM------HP----TQ
2,400----147----323
2,600----166----336
2,800----185----347
3,000----207----362
3,200----223----365
3,400----238----368
3,600----263----384
3,800----281----388
4,000----301----395
4,200----322----403
4,400----347----414
4,600----363----414
4,800----378----413
5,000----382----401
5,200----393----397
5,400----401----390
5,600----410----385
5,800----417----378
6,000----421----369
6,200----422----357
6,400----423----347
6,600----419----333
That is 423 FWHP @ 6,500 and 415 ft/lbs @ 4,500.

 

I think I decided on a cam.
It will be a 224/234@.050, .465/.488 lift, and 282/292 advertised duration on 114 LSA.
It will go in:

• 305 with 9.25:1 compression.
• ported 416's with stock valves.
• performer intake
• holley 600 carb
• 1-5/8 headers
• dual 2.5" exhaust
• th350 with 2200 stall
• 3.36 gears

What do you think of the combo? Any guesses on what power would it make? What would it run in a 3600-3700lbs car. Thanks for responding.

 

That's a strange cam, which part # is it, or what company makes it?

I wouldn't go to that wide of an LSA on a carbed application, it's also a very drastically split pattern, and has somewhat lazy ramps (ie, low hydraulic intensity), 282->224? 292->234?

 

It is a summit brand cam. Is there one you would recommend? Do you think the motor would make 300 hp.

 

Yea, ditch the summit cam lineup first off.

heavy vehicle, lowish stall speed, intake-heads-carb setup for low end. Stick with a low end cam.
comp xe262.

Porting those 416 heads is what's going to win you the battle, do a good job now!