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Discussion Starter #1 (Edited)
:devil:

I am trying to extract over 300 horses out of a 307 with UNDER 1k

Ive been researching a parts list and so far this what I have come up with
Full 2.5 inch dual exhaust with 1 5/8 inch primary headers (got it covered I will have it next month)

1.84 4 barrel heads with 1.94 Intake valves on them (Ive heard you can do this) and a little porting
cam @ 480 480 (this one) http://www.jegs.com/i/Lunati/638/00010LK/10002/-1
Edelbrock performer Rpm
Holley 600 cfm carburetor
Some sort of Hei Ignition


This will be my first engine build and I will be starting it within 2 months but I need people advice on it

The only problems I am running in to are the HEI Ignition (Price) and The HEAD GASKETS! I can't find any for a 3.875 bore!!! can you call someone and have them make you some? I would like the thinnest Possible gaskets so I can bump up the compression a little from stock.

Now I have a limited Knowledge about engines so can anyone help me out with my parts list? I would like to have the most bang for my buck.

I choose most of these parts because there EVERYWHERE and I can find used ones for cheaper.


I really would LOVE not to touch the bottom end if that is possible.
 

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The only thing I would suggest is if you have to bore which would suprise me if you didnt, is to bore it .125 over and make it a 4.00" bore and put 327 pistons in it and you will have a large journal 327. I wouldnt think the 327 pistons would be any more expensive that a .030 307 piston. then your head gasket problem will go away also. If you go to your local "U Pull it" parts yard look for a chevy with a large cap HEI dist with a vacuum advance and it will fit your engine. Any big block or small block.

:devil:

I am trying to extract over 300 horses out of a 307 with UNDER 1k

Ive been researching a parts list and so far this what I have come up with
Full 2.5 inch dual exhaust with 1 5/8 inch primary headers (got it covered I will have it next month)

1.84 4 barrel heads with 1.94 Intake valves on them (Ive heard you can do this) and a little porting
cam @ 480 480 (this one) http://www.jegs.com/i/Lunati/638/00010LK/10002/-1
Edelbrock performer Rpm
Holley 600 cfm carburetor
Some sort of Hei Ignition


This will be my first engine build and I will be starting it within 2 months but I need people advice on it

The only problems I am running in to are the HEI Ignition (Price) and The HEAD GASKETS! I can't find any for a 3.875 bore!!! can you call someone and have them make you some? I would like the thinnest Possible gaskets so I can bump up the compression a little from stock.

Now I have a limited Knowledge about engines so can anyone help me out with my parts list? I would like to have the most bang for my buck.

I choose most of these parts because there EVERYWHERE and I can find used ones for cheaper.


I really would LOVE not to touch the bottom end if that is possible.
 

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I would run a set of vortec heads , a performer eps intake, a summit cam and lifter set 440/442 lift hyd, and your hei with headers and a good dual exhaust should get you your goals....i would imagine that summit or jegs would have a rebuilders gasket kit for that motor. The only other gaskets you should need are the vortec intake gasket....and you can get that from auto parts stores ..jmo :D
 

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Discussion Starter #4
hmm. does anyone know how much a boring/honing usually costs for 8 cylinders

(lets compare it to a .10 over bore)

and also I know that a 307 engine has a 327 crank in it but i think its like .10-.20 under bore

would this be a problem if I went to replace it with a better steel crank?
 

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The last time i had block work done it was 600.00.....hot tank, new cam bearings and freeze plugs...bored .30 over and magnufluxing ......
 

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hmm. does anyone know how much a boring/honing usually costs for 8 cylinders

(lets compare it to a .10 over bore)

and also I know that a 307 engine has a 327 crank in it but i think its like .10-.20 under bore

would this be a problem if I went to replace it with a better steel crank?[/QUO The last time i did an engine it was about $100 but ive done 4 other engines and didnt bore then, if your tring to save money check the bore out if its within tolerence and has no deep scratches then just ball hone it with a drill and get new rings, also you can go as much as .030 on a crank on a street engine. my last 325hp 350 was .010/.020. nice to see someone revive the little 307, personaly i think its better than using a 305 because it has a better bore to stroke ratio and a bigger bore (same as 283) good luck!
 

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Heads are the number 1 priority.

S/R Torquer 305's (will keep compression up and flow well)
Vortec's (64 cc, but flow well)
Aluminum Corvette heads from the late 80's (use center bolt valve covers, but 58cc)
283/327 power pack heads with 1.94 valves installed
305 HO heads with 1.94's installed and ported

I will donate a set of 1 5/8th's SBC ceramic headers if you pay for shipping, the flange isn't quite flat, a little beat up, but they're usable. My dad also has some worked over 305 HO heads if you want to buy them (PM me).

I would use a cam in the .450 lift range. A small lunati voodoo would be the best choice. The one smaller than their 262 adv dur I think.

A used HEI would be fine, but Summit has a new high proformance (Mallory makes it) dizzy for $100. It's a value.

I went 13.8's with a 307, stock converter, th350, 3.73 combo. I used those 305 HO heads and a .454/.454 lift cam, along with a 600 cfm Eddy carb. I daily drove the car and drove it up to Michigan/Canada and else where. It was the most reliable (best?) engine I've had in my car.

Kev
 

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1000 bux and a 307

If i had a 307 that I loved and 1000 bucks that I didn't , this is what i'd do. Its not much money but that may not be a big problem. Ebay could be your best friend here.

I had a 70 Chevelle with a 307 and if my memory is correct it had 200 hp stock with 9-1 compression so we need to add 100 HP.

I hope the 307 is in good operating condition now , a rebuild isn't in the budget for 1000 dollars. The money just gets burnt up too quick in a rebuild.

I assume the 1.84 heads your referring to are from a 305. I remember a build of a 305 that they used 307 heads because of the lack luster exhaust flow of the 305 heads. There used to be some killer 283's in super stock that had to use the 581 head, so i'd say your heads are prolly near the capacity of those. Given the amount of money I would find a friend thats took a set of heads apart , and give them a home grown port job focusing in the area under the valves. I wouldn't get crazy , just smooth them up a bit. If this seems too much , I would look for a set of 461 double hump heads on Ebay or local. They're going for 2-300 bucks ready to bolt on. The 461's have the smallest chamber and will help the 307 the most. A set of new valve springs will be very beneficial here more than you think.

If you want electronic ignition , i'd look into one of these , they're in your budget and I like the centrifigal advance system better on the point distributor than the HEI myself

http://www.jegs.com/p/Accel/827384/10002/-1

that with a good coil and your ignition should be handled with a nice set of spark plug wires.

I like these cams myself and get a good timing chain set , i'd put it in at 4 degrees advanced ,
http://www.jegs.com/i/Crane/270/100172/10002/-1#

Its on a 106 LSA , it should bump up the bottom end , sound better winding up and at idle but may need a 2500 converter to go with it. This will be the most well spent money , and prolly make the 307 feel like it has 300 hp now , this unit is at Jegs for 199.00 dollars and a stall of 2700-3000, which a 307 may not stall it that high , but this will give you more performance and fun than anything you spend on your car.

http://www.jegs.com/i/JEGS/555/60401/10002/-1

I would try to find a 750vs holley ( 3310 ), they're going dirt cheap on Ebay. I won a 750VS for 10 dollars last week , buy a kit , your good to go. You could find a stock Q jet intake and use an adapter plate while more funds become available
 

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Keep us updated Evan i'm subscribing to this thread for sure!

I've wanted to yank the 307 out of my nova and drop in a new 350 for a long time but right now with the way things are going its not going to happen anytime soon. Plus on top of that deep down i've always really wanted to keep this little 73' as close to original as i could with some upgrades for like disc brakes. But the kicker for me was always the cost of rebuilding this 307 to get the power of at least a 350...it never added up...i can buy a new long block 350 and be making more horsepower than this used and abused 307 at the nearly the same price but if you can figure out a way to build a 307 to make 300 horses at under a thousand bucks then I'd definatly be very happy with that set up. 300 horses is pretty respectable for weekend cruiser.
 

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The first question you should ask is how you are going to use the engine? daily driver , drag strip etc?
Then build accordingly. You don't want a race engine for a driver. I've done that..No fun.
I would build it as a street daily driver. you want it reliable and easy on gas.
My brother has a 70 chevelle with a stock 2bbl 307. I put some rebuilt 305 heads on it for him and I could imediately tell the difference.
Don't go too big on the cam or carburator. Don't go to high on the compression. 8.5 or 9 to 1 is pushing it on todays 87 octane gasoline blends. Unless you like paying for preminum or race fuel. Bigger isn't always better.
I would suggest the rebuilt 305 heads ( hardened valve seats) with magnum roller tip rockers, a mild cam like a compitetion cams 252H-260H, no bigger than a 268H, A good dual plane intake like the plain (non RPM) edelbrock performer, A 500 cfm edelbrock carburator but nothing bigger than 600, small tube headers or a pair of ram horns manifolds, and a good HEI distributor.
I personally prefer torque over horsepower. How often does one really drive the engine at 4 thousand RPM on the street? You want your power in the mid range and your torque in the low range where its typically driven.
Just my suggestion.
 

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Unless you are partial to this engine, I would take the money and buy a good used 350 and install a set of headers. It would be a nicer foundation for the future.
Tg
 

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The cam you listed is too big for the 307 for your goals and isn't going to be a good match for what you're building. First off you'll need the 58cc heads to get decent compression. That'll help the most. If you can find a set of 305 heads off a 305HO in a Monte SS or a Z-28/Trans Am they'll work good. You could have them opened up for 1.94 valves as well and will work very well this way for your 307. The previously mentioned Crane cam will work good as well, but will have a pretty nasty idle.A Comp 268 works well in a 307. Also, all the engine needs is a Performer intake and a 500cfm carb. If you find a 305HO in the junk yard, grab the factory aluminum intake as well. That's all the intake you'll need. If you can find a Q-jet to rebuild you'll be set. As you stated, 1 5/8 headers and a decent exhaust is all you need on that side of the engine. With as build like this, you'll want 3.55 gears or so.
 

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Unless you are partial to this engine, I would take the money and buy a good used 350 and install a set of headers. It would be a nicer foundation for the future.
Tg
I second that- I sold my 350 for something like $200 bucks as a long block. Maybe you could hook up with some one that is planning on powering up from a 350 and make a deal to help them pull the motor.

Chuck
 

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Discussion Starter #16
Honestly I know I can run out and build a 350 for cheaper and make more power, but in my eyes it just seems like what everybody is doing and seems dull to me. I would Love to have a bbc right now but that is not in my budget and will have to wait until i can dish out 10 k for a motor and driveline.

so I decided that building a 307 would be cool to me. no one is doing it. its affordable and I know I can squeeze some power out of it with the right set up.
 

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Discussion Starter #17 (Edited)
and I think I have the heads covered now but Ill have to wait a couple months before I start this project. :(


But I will defiantly keep you guys updated on this project.:devil: as things progress with it


Does anyone have any suggestions for reading material?

I know there's a book out there one rebuilding the sbc,but is there one for hot rodding?
 

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How to build small block chevy's on a budget by David Vizard is a excellent read for budget builds such as yours..........It has tons of great ideas and tips on anyones budget :D
 

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In my research, the best pick for a built 307 is an XE262 cam. It was perfect.:yes: On a 10:1 307 with headers/mufflers and a 650cfm carb, Desktop Dyno said peak torque was around 400 at 5500rpm, with peak torque of 435 or so at 3500rpm. Torque curve was relatively flat, varying only 10-15 foot-pounds from 2500-5500 rpm.
 

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Discussion Starter #20
In my research, the best pick for a built 307 is an XE262 cam. It was perfect.:yes: On a 10:1 307 with headers/mufflers and a 650cfm carb, Desktop Dyno said peak torque was around 400 at 5500rpm, with peak torque of 435 or so at 3500rpm. Torque curve was relatively flat, varying only 10-15 foot-pounds from 2500-5500 rpm.
do you have a link on that?

thank you
 
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