Hy guys,

I've been planning on some upgrades for my 283 for about a year now and have been collecting some parts along the way. These include a new Lunati cam (216/228 @ 0.050, .454/.480 lift) and a set of ported 305HO (14014416, 58 cc) heads. I have had a 30 over 327 sitting in my garage for some time now and decided to put it in at the last minute and use the new cam and heads. I currently have an edelbroch performer, 4 BBL qjet carb, HEI distributer and 1.625 headers and 2 1/4 manderel bent exhaust with dynomax mufflers.

What HP and TQ do you think this combo will produce? Are the ported 305 heads going to significantly hurt the airflow on the 327? I'm out of money so this is what I'm going to use. I was hoping for around 325/350 hp and torque. Lunati was estimating around 280-300 with the 283 so I/m hoping for around 325/350 with the 327.

Clyde

325hp or so sounds like a "keeper" for your 327, imho!! Depending on it's CR.??

Didn't D2K her, tho..

pdq67

the 305 heads should be ok for around town cruising. the 58cc chambers will bump your CR up quite a bit. especially if your block and head surfaces are milled, but your upper rpms will be a little weak in terms of airflow. you'll probably want a big cam to help on that. calculate your CR to see how much cam you can support.... those heads were restrictive on 305s in the upper rpms stock, so it won't be any better with the larger cubic inches. the 327 is going to want to rev with its short stroke. the 305s will definetely do in a pinch, especially when you're short on $$, but will need work to breathe if you want to make that 327 scream.

I ran the numbers on Pat kelley's DCR and cam up with 9.7 static compression and 7.82 on dynamic compression. I'm hoping the porting will help the 305 heads breath better at the upper RPM's. I don't plan on taking her past 5000 RPM's much anyway. Maybe 5500 on special occasions.

The 327/350 cam had 222/222 duration and slightly smaller lift than my cam so that's why I was hoping for around 325 HP. Do you think it will be able to do it?

Clyde

I think you would be hard pressed to make that unless your running the 1.94 intakes valves. If your running the standard 305 valves they are like 1.80 or something. I would think you would be lucky to hit 300 at the most. Your compression should be up there with flat top pistons.

Just for a little info on the 416's castings. They are the same head that came on the LG-4 305 with 150 hp as the L-69 HO.

The only differences in the engines are the flat top pistons in the L-69 compared to dished in the LG-4. L-69=9.5 to 1 LG-4=8.6 to 1 1983-1986.

The rods are supposedly beefier in the L-69. As well as a camshaft with around .430 lift compared to the .350 lift in the LG-4.

They used the same aluminum intake but used a richer q-jet in the L-69.

Your engine would benefit much from a set Vortech or Sportsman 2's when you get the money (50+hp), but while your saving the 305 heads will work fine.

Some guys on Thirdgen.org are getting some pretty decent flow #s out of 416's. Theyre not really a bad head. Search for F-Bird'88 there.. i beleive he has flow #s for these heads ported and unported.

I have a 0.040 over 327 in my 87 formula. It's got flat tops, an XE256 cam, edlebrock performer, shorty headers, single 3" exhaust, and a 70s era quadrajet. I'm running a set of 78 vintage 267/305 heads casting #450. They've been modified with 1.94 intakes and the chambers are cnc'd to open up around the valves, making them 64cc. They are junk compared to 416s. Last year on the chassis dyno this combination put down 227hp at 5250 and 266 ft/lbs at 3500. It was only 2 hp off from an 89 L98 tpi motor. Not bad for a real mild cam and "crappy" heads!

Edit: forgot to say my 327 is backed by a th350, and the l98 was running a TKO.

you know i read on this post and others how every one down plays the 305 heads............oh you going to loose flow on upper end bla bla bla...........i swear there is so many wannabes out there who think they know what motor will do makes me sick sometimes.......makes me wonder how many really have built a motor with 305 heads or smaller engines..........i tell you what i built an old school motor and put it in a dumb ass stationwagon just to prove a point to alot of my friends who down play 305 heads and motors specially


i took a well used 305 engine that had 80,000 miles on it that was in very sounds condition and put some z28 springs on the stock heads and i put a 305 comp cam in it (hyd)......put steel shimmed head gaskets on it compression still under 9.0 to 1 and put a victor jr on top of it and a 850 holley double pumper with a hei unit, open headers and put a 4000 stall behind it with 4.56 gears all in a 81 malibu station wagon........the car shifted at 7000 rpms and ran 13.6 thru the 1/4 mile at 103 or so mile per hour........

so you can pencil an engine combination to death on paper.......but building one and seeing what happens says alot more..........

i run a set of 305HO heads on my 283, and they definetely do cause a loss in the top end. a set of Vortecs would be a definite improvement. my combo has 10.2:1 CR with a healthy hyd cam, and 600cfm carb, and she starts to wheeze around 4000rpms, when she should be pulling a bit higher.

Chevy mad you are hitting around the 300 hp mark with your 327. With better heads you would hit around the 350 hp mark. I am just curious what are the flow numbers on the 450's compared to the 416'? I would not think there is that much difference. Sure you can spend the money and put the bigger valves, port work and such but why do that. Start out money ahead on some newer designed heads or even the double humps. Heck the new heads usually already have 2.02 valves, good springs and are a new casting so it is a better starting point.

With close to 300hp and a 3.42 gear and a 2500 stall or thereabouts you should be hitting close to a 14.00-14.20 with traction and good conditions.

Just think with the cam that Clyde is using and a set of double humps and small domes the L-79 put out 350 hp.

It's a compression/intake valve closing thing!!

A 268/270/272 cam is fine at about 9.75 to 1 CR. on pump gas

pdq67

I have run 327s with the old 283 Power Pack small valve heads. They are done a 5000rpm but build very good low and midrange torque. I bet the 305 heads will act about the same. If its just a driver you might be happy and they might get some decient gas mileage.

I have a set of the 283 power packs on my current 283. When you compare them side by side, the 305 heads are significantly larger on both the intake and the exhaust. Sounds like the best that i can hope for is a tourqey motor with low and mid ring but not alot on the upper end. I can live with that as long as it will smoke the tires on command. I have a set of Richmond 4.10's setting on the shelf just waitng to be put it.

Clyde

The 416 heads have the same ports as the l89 350tpi heads. They're decent heads. The 450s I have are very small ports. The difference is visible to the naked eye even. I didn't spend much fixing these 450's up. I needed a cheap set of heads to get the car running because the original heads didnt have accessory holes, or 7 hole exhaust. So I ordered these from a place in Arizona, $299 delivered. Couldnt beat the price.

Flow #s for 416s ..stock: 195cfm@.500 in.(182@.400") and 110cfm@.500 ex.

ported:225cfm@.500 in. and 140cfm@.500 ex

Thread on porting them with lots of pics http://www.thirdgen.org/techbb2/showthread.php?s=&threadid=117410


Porting templates: http://www.thirdgen.org/techbb2/attachment.php?s=&postid=1341984

With those templates you end up with a 177cc intake and 64cc exhaust port.

Lots more info on these heads on that site. Seems the biggest problem with them is the small valves. 1.94s are the best thing you can do to them.

My junk 301 with the junk -097 coffee canned lifters solid cam still ran right up there above 7,000 rpm EASY with '55, 265 small valved heads that I ground on!! I figure she was hustling to make 300, maybe 315/325? hp up top??

Boy, I loved ta hear her sing with my 2" caps off going through the gears!! She would go up until the points bounced... AND then I would back off her AND wind her up again!!!

pdq67