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325 horsepower 305 cid Chevrolet V8 (Built with simple bolt on mods!)

  
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325 horsepower 305 cid Chevrolet V8 (Built with simple bolt on mods!)

 
Newty-Newt Newty-Newt
New User | Posts: 9 | Joined: 01/09
Posted: 01/30/09
05:46 PM

In an article dated March 1999 there was an in depth article on getting 325 hp with different stages.
305 BUILD-UP PART 6: Added Comp Cams XE262H-10 "Xtreme Energy" hydraulic flat tappet cam. Replaced World Products 305 S/R Torquer heads with '96 - '97 Chevy truck L31 Vortec cast iron heads, GM P/N 12558060. The Vortec heads require a different intake manifold, and chose an Edelbrock Super Victor. They kept the same Holley 750 DP. These heads are a bolt on for conventional small block Chevy engines. If your engine is earlier than '87, you will also need a set of self aligning rocker arms, and a pair of "center-bolt" valve covers. My question is, in the last 9 yrs, is there a better streetable combo that makes more hp and runs with a stock 700r-4 auto.  Smile  

SMOKESHOW SMOKESHOW
Guru | Posts: 1001 | Joined: 09/08
Posted: 01/30/09
08:24 PM

If you look around, you will find dozens of builds in the last 10 years that will easily outperform that 305.  Take any 350, put a set of affordable aftermarket heads, a decent dual plane intake a 600-700 cfm carb, and a reasonble cam in, and you blow the doors off that 305.

Get a vortec 350, swap the cam out for another mild roller, put a performer rpm and a demon 670 on it and you will see 375hp and 400fp below 5500 rpms.

Read up it's everywhere!!  

Newty-Newt Newty-Newt
New User | Posts: 9 | Joined: 01/09
Posted: 01/31/09
03:46 PM

I appreciate you trying to steer me to a 350, but that is not what I plan on doing. In 99 they did an in depth dyno test on a 305 with over 80k. Step 1, had dyno readings just headers. Step 2, added Edelbrock Performer gained 20 hp. Step 3,chgd to 750 holley w/no chg in hp. Step 4, Added Comp Cams XE262H-10 "Xtreme Energy" gained 53 hp. Step 5, Chgd heads to World Products 305 S/R Torquer made 300 hp. Step 6, Changed heads to Vortec GM P/N 12558060. and got 325 HP from a stock 80k 305. All I'm asking from all the engine experts, has anyone gone further in the last 9 years on the dyno and got a better bolt on combo to run with a stock convertor 700r-4. Looking for the best of both worlds, gas mileage with smaller bore and hp.  Hopefully I will have less fill ups driving my 305. I may even try E85, I hear that alone makes more hp.  Smile  

Pontiacman2 Pontiacman2
Moderator | Posts: 8956 | Joined: 09/08
Posted: 01/31/09
04:22 PM

PHR did a 305 chevy build and got 370 HP out of it.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

SMOKESHOW SMOKESHOW
Guru | Posts: 1001 | Joined: 09/08
Posted: 02/01/09
11:58 AM

With a stock converter?  

Newty-Newt Newty-Newt
New User | Posts: 9 | Joined: 01/09
Posted: 02/01/09
07:32 PM

Do you know what month/yr PHR issue that was?  

SMOKESHOW SMOKESHOW
Guru | Posts: 1001 | Joined: 09/08
Posted: 02/05/09
12:12 PM

Pretty Good Article, the only thing that is weird is the milling of the aftermarket heads.  The numbers are made without parasitic draw of accessories and with premium dyno headers, but impressive all the same.
http://www.popularhotrodding.com/enginemasters/articles/chevrolet/0667_phrs_305_chevy_engine_blocks/index.html  

Newty-Newt Newty-Newt
New User | Posts: 9 | Joined: 01/09
Posted: 02/05/09
07:01 PM

Thanks for the info  

SMOKESHOW SMOKESHOW
Guru | Posts: 1001 | Joined: 09/08
Posted: 02/06/09
08:35 AM

No problem, I'm not sure that engine would like a stock converter and highway gears all that much, but impressive numbers all the same.