ive got a 305 that im dropping in my 85 camaro and its on the engine stand right now waiting for a new cam (comp cams 292h-10 grind). i hear there are pretty good gains to be made, even with a 305 in getting the heads machined. i have an old set of 305 heads (416 castings) that i cleaned up to get ready for the machine shop and i pulled the valve cover off the ones on the motor already and the heads on there are 416s as well...

now the question is does it really matter which set i take, because the ones from the old motor have been sitting and have rusted which would require me to put new valves in it. the ones on the motor have perfectly fine valves (motor only has 20,000 on the clock). would it be worth my money to just buy a set of manley or similar high performance valves for a 305? or should i just get a valve job on the ones i have, or leave them stock?

and an even better question, is it really worth machining 305 heads? if so what all should i get the machine shop to do? i really dont want to dump too much money in this motor as i am saving to build an all out race motor to put in there anyway...thanks for the help

curt

 

It really depends on what you want. I run 416's on my 350 for a couple reasons...
It was better than the swirlies I had, and it boosted up my compression ratio.
If you are going to go through the trouble to get it machined you have to ask yourself what you want.
You said you wanted to build a race motor... so do you want to just use these to get you by or make these decent?
If so, then take any set, tell the machine shop, to hot tank them, install new springs and valve seals... as for the valves... this again depends on what you are looking for. (Cam, etc) You can get some new valves for a decent price at summit or jegs. You could even go bigger for your intake valves. upgrade to 1.92's even.
They arent horrible heads... there are alot of worse heads, but since you have them you can upgrade them easy. Use one of those sets of heads and practice hand porting. every little bit helps.

 

i thought about practicing porting them myself, but my dad said i would be wasting my time as he has been building race engines for close to 25 yrs and said even he couldnt port his own heads.

as for what i want to do with the car id like to throw a decent rearend under it with low gears, little bit of a stall, lighten it up (hopefully around 3200 lbs), set of drag radials, and a 100 shot of nitrous and see what itll do at the track.

i really dont want to just use the heads to get me by until the new motor goes in, i really want to see the true potential of what can be gotten out of the 305 (just for the fact everyone shuns them because of its big bro the 350) but i dont want it to cost an arm and a leg in the process because to me that defeats the purpose...

 

if this is what you felt from the get go then what was the point of making this thread?

 

my point of making this thread was to ask for personal experience with the 416# heads as i have none. i wanted to see if it was worth my while and my money...

 

They have worked fine for me in my 305 now its in my 350. Not sure why your dad cant port its not hard at all... just very very time consuming. you never said what you wanted to do with this motor and what cam... without that how can we decide what heads are right for you.

 

im looking very hard at the comp cams 292h-10 cam..(244, 244, .501, .501) as hot rod mag built a 305 with this cam and put out 400 hp on the engine dyno, but i know that most of that power was made in the heads (they used RHS 305 heads with manley pro flo valves with mild port job)

im really not worried too much about the engine running on the street as it will mostly be a strip car (something to have fun with on the weekends) so id really like to get the heads to flow better at higher rpm's. if you say i can port them myself i have the patience to do it and am willing to try if you could point me in the direction of what tools to look for to do it with. like i said earlier id just like to see what can be gotten out of a 305 without too much effort, just to go against the grain ya kno? i plan on keeping the stock bottom end and running small tube headers, single plane manifold with about a 650-700 cfm carb with a 100 shot of nitrous.

i appreciate the help

 

I also run the 416 heads on my 350.

Do a search on porting 416's. There's TONS of threads on it. I think they're the most commonly ported head casting on TGO, for good reason.

Sitting bull, and f-bird'88 both have written good info on this topic. Fbird has also had some of his bench flowed, and shown good results.

I upgraded mine to 1.94" intake valves, and backcut the stock 1.5" exhaust valves. Bowl work nets the most gains, and you can deshroud the valves if you want a larger combustion chamber, or if you've put in the larger valves.

 

You can use those heads for that cam but they will have to be machined. Stock wise the heads can handle .480 lift, above that and its probably a good idea to get some work done.

 

thanx i printed out the article on doing the headwork yourself and have researched the pricing of doing it and it seems like the logical idea if i have a pair of heads to spare.

nelapse...thanx for your help as well i will look into getting them machined (pricing, etc.)

i will keep you updated on the progress

 

well here is the update...

i brought the heads from my parents house to NC with me last weekend and just picked them up from the machine shop. i payed them $30 to clean them (acid vat) and have them magnaflux them. showed up no cracks and they look pretty decent.

i just got back from the hobby shop on base where i took the valve springs, locks, valves, etc out along with the rocker arms. it cost me $2 to use a workbench and all the tools i want for as long as i want as long as they are open.

they do have a pnuematic die grinder and i am ordering the kits mentioned in the article Standard Abrasives wrote (Deluxe Porting Kit, and Gasket Removal Kit). any suggestions or anything else i need to know before i give it a try?..thanks..

 

not sure what's in those kits, but I don't think they have carbide burrs...?

Carbide Burs, Cutting Tools, Endmills, and Accessories
SH-2 DBL - 3" flame tip. Good for easy access bowl work, and chamber work. Flame tip helps get small areas. $10
SC-3L6 DBL -cylinder, ball end, 6" double cut. This is for doing deep in the ports, and deep in the bowls. Ball end is needed, rather then flame tip. Long ones you can't run fast, else it gets wobbly and scary. $15
SC-3 STD - $10. If you can afford this, it's just like the above one, but shorter. You can use it for the port entry, and the bowl and chamber. This was my favorite one to use, bread and butter.

rocker studs, what's the plan?
pin? $5, some work involved. Easiest/cheapest. Need drill bit and roll pins and drill.
collarless threaded stud? $30. Need tap, and washers to pull out studs. Good solution, what i've used.
collared threaded stud? $60+ - need machine work, need guide plates. Need studs, plus machine work, so $60 + ??. Best solution, probably not needed in your case.

 

Yes, a "tree" carbide burr is very helpful for getting the big amounts of material removed (make that "big" amounts of material), and for getting in around the guides.

Think again about that cam. It's the Magnum series, from the look of it - single pattern, old-school, peaky. Consider the XE284H instead - slightly more lift, slightly less intake duration, slightly more exhaust duration - overall a much better torque curve with pretty much the same peak horsepower. It'll still be pretty wild in a 305. I hope you have good rod bolts, have pinned the rocker studs or have them replaced with screw-in type, and are using aftermarket rockers (we already know very good valve springs, right?). And forget about "a little bit of stall" - you're going to need at least 3000 RPM stall (the Magnum would need even more).

A dual-plane intake like an RPM or Stealth would be better than a single-plane. Especially if you don't have a bunch of stall.

Bottom line - this is a big plan for a little 305. You're going to need a stout rotating assembly, up-to-the-task valvetrain, and no handicaps in the drivetrain (like "a little bit of stall"). Understalling is a much greater problem than overstalling.

 

thanks for the input and that xe284h looks a little better for what im looking at doing. yes i kno itll need about a 3000 stall (comp recommends 2800) but i didnt want to say a lot and someone misconstrue it as me saying 5000 or something.

as for the studs, my machine shop is putting in screw in type along with guideplates as i would like to run roller rockers (1.5 procomp). and for the single plane i was looking at either to torker from edelbrock or the wieand X-CELerator, and running either 4.56 or 4.88 gears.

i looked at the different carbide bits you recommended and decided what the hell ill order all of them and try em out. if you say they work then you have more experience than i do in that department so ill go with it...