383/385 220cc head concerns

[rod1107]

What’s up guys. I have a 385 sbc shortblock ready for heads to be bolted on. The motor consists of a 4340 rotating assembly. 6in rods with je/srp 11:1 flat tops (with 64cc heads) cam is a custom grind solid roller from Cam Motion and the specs are as follows

613/568
246/252 @ 50
110 LS
23 valve lash
35-6500 rpm range

Heads are eBay 220cc el cheapos
Flow numbers seem a little too “advertised” but they are

@100 68-53
@200 143-112
@300 196-163
@400 244-199
@500 262- 226
@600 299- 239

If these flow numbers are in fact what they say they are how streetable would this combo be? Not really looking for streetable though, the car is a 1985 Cutlass full weight (3500lbs give or take) and will be driven mainly on weekends and an occasional trip to the track. Transmission is a pretty stout th350 with 3500 stall converter with 411s out back.
My only concerns is the heads being too big? Any suggestions would be greatly appreciated. Thanks

 

[MrSony]

Engine Masters did a video on cylinder head runner size. May help you decide.

 

[Streetbu]

You have them, I'd use them... Maybe just a tick, but probably not enough for you buy new ones

 

[64nailhead]

1st, that cam is not what most anyone would consider 'streetable'. That doesn't mean you can't use it on the street, but it's going to be somewhat of a PITA in city driving. With that in mind, not everyone's city driving is the same either. Downtown NY or Philly without any highway speed driving will be extremely tough. For me though, we have a tough time getting stuck in traffic for more than 5-10 minutes.

With that in mind, I 2nd Streetbu's recommendation. And those heads are not to bog for the cam you're running. It should really shine over 5500 rpm's. Hopefully you have a set of springs that Cam Motion recommends. Also, you'll need a set of roller rockers. A set of 1 3/4" long tubes will help a bunch as well.

 

[bracketchev1221]

How did you get a custom grind cam without knowing what heads you were using? If the cam was not designed around the heads its an expensive guess at best. With that being said, you have the heads, I'd use them.

 

[rod1107]

How did you get a custom grind cam without knowing what heads you were using? If the cam was not designed around the heads its an expensive guess at best. With that being said, you have the heads, I'd use them.

It was used in a previous build with dart iron eagle 230s and ran pretty good to me that is

 

[lilbowtie]

I think you already know you have a mis-match just questioning how bad. I would truly like to know what the cam was designed for with the split lift and duration along with the high lift and lower duration (not the gentlest on valve train). Just about the time your getting up in rpms for the heads to start breathing you run out of cam. As said, you definitely need the springs for that cam and setting install height should be fun. Also make sure your valve train geometry is correct. MrSony's vid shows the mis match of head to cam - the correct cam with the 220 heads would have that engine over 600 HP. The question is where do you want to make power? I would suggest having a chat with Cam Motion and see if they can shed some light on this. Rod I see you made an entry as I was going to submit - do you have any 1/4 mi times and what combo.

 

[rod1107]

I think you already know you have a mis-match just questioning how bad. I would truly like to know what the cam was designed for with the split lift and duration along with the high lift and lower duration (not the gentlest on valve train). Just about the time your getting up in rpms for the heads to start breathing you run out of cam. As said, you definitely need the springs for that cam and setting install height should be fun. Also make sure your valve train geometry is correct. MrSony's vid shows the mis match of head to cam - the correct cam with the 220 heads would have that engine over 600 HP. The question is where do you want to make power? I would suggest having a chat with Cam Motion and see if they can shed some light on this. Rod I see you made an entry as I was going to submit - do you have any 1/4 mi times and what combo.

Correct. If you haven't already noticed I am a "noob" I'm still trying to understand different cam durations. My biggest fear is to have a car that sounds like a pro mod but runs like a school bus. It's just not acceptable. I would like to make power from about 3500. I am very open to different cams as you mentioned the right cam would have me at 600.. what part # might that be? I was told I should look into comp cams '306s' a solid flat tappet with 555/555 valve lift and 260/260 duration @50. As far as the setup with that cam all I know for sure is that it was a 355 with gas port pistons single plane intake and dart 230s. Only times I can give you are the times I almost stained his passenger seat. The torque was amazing and this setup was probably also mismatched but it sure felt good. I would like to keep the heads and swap out the cam if I can get one to match. I don't care about it being solid roller or mechanical flat tappet. Preferably mechanical for price reasons. I have roller and solid lifters

 

[vanrah]

Greetings Rod1107 & all; I've been reading along some what. You got some good feed back from our excellent members. Now keep in mind this is free & you may get what ya pay for?? Ya got a lot of intake runner for a non race 383-385, but with the cam ya got it may be unfriendly in any traffic. Only you can determine where your line is in the sand, "Street-able is Very Subjective". And if ya de cam it too much the heads just won't have enough viscosity to keep you mixture atomized. Since ya already got the solid rollers, a cam & maybe push rods will get ya going. If you back down to a 230*-236 @ .050" you might be able hit a very nice compromise? Do not over carburetate with this set up 650 DP max or a 750V max & consider a 650 HP Vac as ideal.

 

[bracketchev1221]

I agree with contacting cam motion and telling them what you have and see what they say about the cam. It is possible that they can regrind it somewhat to be more compatible to your setup. At the very least they can tell you how it should react as far as peak power and peak rpm.