rebuilding and addn performance 86' v8 307 engine

[coolcut86]

need help on rebuilding and addn performance to my v8 307 engine. I want to keep the car as original as possible but still have alil speed under the hood without changing the engine. Any suggestions out there on intake, headers or overall performance parts in general? thanx.

 

[drogg1]

Yes to headers, cam if you can manage the swap, intake if you can find a cheap aluminum dual-plane(i.e. less than 150), K&N(added out of habit), perhaps a smaller(600 cfm)Holley or Edelbrock(I recommend single inlet, vacuum secondary, electric choke)carb or non-computer Quadrajet from 76-80 GM vehicles with a similar engine size, non computer distributor from 76-80 GM vehicle or aftermarket street distributor. You will also be limited by your likely VERY tall rear gear ratio. I recommend either replacing the gears with a lower ratio, such as 3.23:1, or swapping out the entire differential from a different G-Body, preferably one with a posi.

I'm not very good at conveying information well so please feel free to ask any more questions.

 

[megaladon6]

or switch to a chevy 307.
😀 sorry, couldn't resist
unfortunately the 307 is not capable of much power without lots of money, maybe not at all. but for what you can get--what he said and dual exhaust (2-2 1/4in)
or, if you're doing a rebuild, deck the block and heads to improve quench and compression, port/polish the heads (and hopefully some good olds 350 heads will fit instead of the stockers)

 

[joe_padavano]

or switch to a chevy 307.

Right, because THAT was such a powerhouse...

As noted, the best and easiest performance increase for a 307 is to swap it out for a 350 or 403 Olds motor. The motors are externally identical.

 

[megaladon6]

but it's a chevy! but seriously, wasn't one of the old (1960's or so) 307's a halfway decent motor?

 

[3rdgentug]

but it's a chevy! but seriously, wasn't one of the old (1960's or so) 307's a halfway decent motor?

not really by todays standards
well even for those days either 😀

 

[joe_padavano]

but it's a chevy! but seriously, wasn't one of the old (1960's or so) 307's a halfway decent motor?

From Wikipedia (and yes, I am painfully aware that Wiki is not always correct):

The 307 replaced the 283 (but are the same engine block with a longer stroke) in Chevrolet cars and produced 200 hp (149 kW) SAE gross at 4600 rpm and 300 lb·ft (407 N·m) of torque at 2400 rpm in the 1960s. The later emissions-modified versions produced just 115 hp (86 kW) SAE net, giving the engine one of the lowest power-per-displacement ratings of all time. Chevrolet never produced a high-performance version of this engine,

So basically, the 200 SAE gross HP that was the most the Chevy 307 ever produced was LESS than the 180 SAE net HP rating of the VIN Y Olds 307 - which had 1980s emissions equipment! And 115 HP for the Chevy with the emissions equipment? :shock:
Gotta love the almighty SBC...

 

[High Roller]

Building a Street 307 Olds

The almighty pre-smog Chev 307 with only 200 GROSS HP :lol: I thought that WAS the high-performance version!! Good one Joe! I could keep up in my wheelchair :wink:

Anyways welcome to the site coolcut86.

If you plan on a total rebuild, and keep it running on the computer as well, here is link where i listed how to improve the Olds 307 for another. viewtopic.php?f=13&t=14156#

Yep good idea to install a posi, and 3.73 gears like the 442's came with. Also Hooker has a good Cat-Back mandrel bent 2.5" dual exhaust system #16810 $370.

 

[olds307 and 403]

You have the swirl port heads, much more limited. A good multi angle valve job and pocket porting a long with a little bigger roller cam would improve it. Problem is low compression and expensive to build up. A stock 403 will be tons faster than your stock 307 and similar mileage.

 

[HighHPCouch]

For all of you non beliving chevy lovers here is a little article you can read its about a 435hp OLDSMOBILE 307 😀
http://www.popularhotrodding.com/tech/0911phr_oldsmobile_307_engine/index.html
This guys did it on a budget not sure what it was though.......