How to make a BOSS'ish 302?

[RAMBO TECH]

I need my 302 to get to 7k rpm, because I have 4.86 gears. The car (a 67 coupe) was a dragster and I like the gears like that. It has a C4, 9" detroit locker, 3500 B&M super hole shot conv, B&M strip shift kit. The original 289 was blown so my dad had someone put a 302 out of a 83-87 Fairlane in it. I'm working on the carborator after reading a ton. I took off the intake manifold and found the wrong gasket(half blocking 1 coolant passage on each side). I probably will not do a rebuild for a while, but I've been reading on that too a little and thought I could use some advise. I also like the carb (holley 4010) and manifold (holley contender), but it's a dual plane and I've read they are not good for high rpm. 302 w/600 cfm carb at 100% VE should get me close to 7k. The heads are 289 6k11 and something and are suposedly hot. 1.5" headers w/dual exaust should allow good breathing. I want to keep it under the hood (our little secret). I think it has stainless steel valves and crowler roller rockers too. In the trunk I have the old blower, intake manifold, pistons, and cam. I've read that light recipocating parts (piston, rods, and pins), and high compression is important. Plus strength. Now I'm finding I might need a better (balance) crank and lifters or something to handle the higher rpm. So, will this carb-manifold do? Cam 2800-6200 or 3200-6800ish RPM? I know I'm a noob but your thoughts would be appreciated.

 

[jdowen2]

By the time you update the current engine with new parts and labor you could get a crate motor.

 

[gsxrken]

I woudn't build a $6000 motor to match a $200 gear set. I'd get to a Barnes and Noble bookstore and start reading how-to hiigh performace related titles. It's fun, and I guarantee you'll go faster AND save thousands in the long run.

 

[gsxrken]

Repost

 

[Dan H]

You may want to think about a 4 or 5 speed manual transmission swap or dropping the gears to 4.30, 4.10, or 3.91. That would let you run a better street engine setup at lower rpm with low final gear ratio.

The dual plane manifold should be fine for up to 6500 rpm. The biggest changes needed for 7k operation are stronger short block (crank, rods, pistons) and cam, pushrods, & valvesprings.

 

[D.Hearne]

To get it to rev to 7-7500 rpms, you'll first need better heads. Then a cam. I built a roller 5.0 a couple years ago that would rev to 7500 with the stock bottom end. Only thing I changed was the rod bolts. Cam was a Ford B303 roller with 1.7 rockers , heads were Canfield's with 1.94/1.6 valves. Intake? That's a new one for me, never heard of a Holley Contender. To get it to rev that high also requires good valve springs that match the cam.

 

[chepsk8]

Like above, Heads & valvetrain are the key. Not to mention you will need a cam that makes power that high.

 

[Bullitt]

Don't forget lifters.

You could get hydraulic to rev that high, but generally be easier to go with mechanical.

I'd really change the gears if I were you... at least if you want a street car. 4.11s are plenty, esp if you run a 5spd with a low first gear.

 

[D.Hearne]

Don't forget lifters.
You could get hydraulic to rev that high, but generally be easier to go with mechanical.

Yea, I forgot those. I had to switch to Crane's stock style replacements to get it to rev to 7500, the factory rollers floated at about 6500.

 

[RAMBO TECH]

Everyone tells me to change the gears. I like the idea of a fast start and don't want speeding tickets. I would like a T5 but don't know if it'll fit in a 67. The Idea is to gain the experience of building an engine and Hope that I do a good job. I could change the gears, buy a new bigger engine and be like everyone else, but I want something unique. So, since I won't even have a garage for 2 years, I have plenty of time to think-dream. Thanks for ya'll's input so far. Summit parts catalog has cam:$120-250, piston:$200-500, connecting rods:$300-550, + other:$250-600. I don't plan on spending $6000. I hope my heads a good enough. They are ported(but I'm not really sure what that is) and the same that were on it when it was a drag racer. How do I know how aggressive of a cam I should get. Really 6500 rmp with torque would probably be good enough. I want more but don't want high maintainance or probability of failure.

 

[mfp4073]

Your overall money is better spent in a modern overdrive manual transmission swap. With what you are describing your goals, that would better meet them than completely overhauling a motor AND would get you gas milage and cruising ability too.....just my couple of cents

 

[steel1212]

Well I'll have to agree with what everybody else has said. If you switch to a 5 speed, even the z series with the lower first gear, you'll never use first on the street. I barely use 1st now with 4.11s and I'm going to switch to 3.70s. With the 4.11s and drag radials it takes off like a bat out of hell and unless your just drag racing the car I don't see the need for the 4.86 unless you just want them so you can say you have them.

With that being said I think a boss 302 was a 302 with cleveland heads right? You'll spend a fortune to replicate that engine as I think the intake will be hard to find. I would go with a tri power or duel carbs if you going the, "look what I have" route. Also you might also consider a roots blower through the hood, that would go along well with those gears. Also if your wanting to drive around a 7k on the street I'm thinking it won't last very long like that unless you spend over 6K for high tech parts. If you go cheap....well you get what you pay for. I'm not trying to be a smart arse just trying to give you ideas that i think you might like.

 

[RAMBO TECH]

I know I will be @4k rpm @70 mph, and plan on adding a gear(at [email protected]) and maybe going manual,(would be fun but I might be hard on a clutch). I would not build it so am not to concerned about it yet. Thanks for input. I agree manual would make it more street driveable. I guess some don't read, because I said I wanted it under the hood. If you look at pic you will see how it used to be. It had nitrous and that's why I was thinking the heads would be good, but not sure why. I think a faster than stock cam(and more compresion)would be a good addition to my situation and a good learning experience. The Holley Contender is mentioned in a article Hot Rods 10 steps to power, but besides that I don't know either. Thanks again. And no I'm not thinking anyone's an arse.