Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

double hump heads on a 305

Thread Tools
 
Search this Thread
 
Old 02-24-2003, 05:45 PM
  #1  
Senior Member

Thread Starter
 
irocbarry's Avatar
 
Join Date: May 2002
Location: Montana
Posts: 663
Likes: 0
Received 0 Likes on 0 Posts
Car: 85 IROC
Engine: L-69 305
Transmission: T-5 manual
double hump heads on a 305

i just found a set of doulble hump heads in my grandpas old elcamino and he said i could have them

i was wonderin if they would work on my 305 if they have the 1.94 valves


would they be a good improvement, i would probably do a cam swap at the same time, so i know that would help
Old 02-24-2003, 05:52 PM
  #2  
Supreme Member

 
ME Leigh's Avatar
 
Join Date: Jan 2002
Location: Valley of the Sun
Posts: 3,852
Likes: 0
Received 0 Likes on 0 Posts
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
Don't do it it will be much worse. They have 64cc chambers compared to your 305 heads with are 58cc, so you will lose some major compression. They probably will not have accessory holes in the front of the head, yours will not bolt up. Plus double hump heads were the **** back in the day now they are just ****.

If they are in good condition and have not been rebuilt grab them and sell them to somebody restoring a stock classic car.
Old 02-24-2003, 05:58 PM
  #3  
Senior Member

Thread Starter
 
irocbarry's Avatar
 
Join Date: May 2002
Location: Montana
Posts: 663
Likes: 0
Received 0 Likes on 0 Posts
Car: 85 IROC
Engine: L-69 305
Transmission: T-5 manual
i figured i would have to rebuild the heads and i was thinking about getting them shaved closer to a 60 cc cumbustion chamber, to give a lot better cr,

what about going to a higher compression piston
Old 02-24-2003, 06:04 PM
  #4  
Supreme Member

 
ME Leigh's Avatar
 
Join Date: Jan 2002
Location: Valley of the Sun
Posts: 3,852
Likes: 0
Received 0 Likes on 0 Posts
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
Why, those heads are not that good by todays standard at all!!
Old 02-24-2003, 06:38 PM
  #5  
Member
 
Aron213's Avatar
 
Join Date: Dec 2002
Location: Florida
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
Car: 88 Iroc
Engine: 350
Transmission: 700r4
Barry, another thing to think about when trying to put 350 heads on a 305 block is the fact that even with 1.94/1.5 valves the area that they cover is as large or larger than your bore. So what your asking the income air/fuel to do is make two 90* turns to fill the cylinder. Also to get down around 60 cc you would have to surface close to .030 off the head which would probably require some surfacing of the intake for proper fit.
Old 02-24-2003, 07:37 PM
  #6  
Moderator

 
Vader's Avatar
 
Join Date: Jan 2000
Posts: 19,349
Received 216 Likes on 177 Posts
Re: double hump heads on a 305

Originally posted by irocbarry
i just found a set of doulble hump heads in my grandpas old elcamino and he said i could have them

i was wonderin if they would work on my 305 if they have the 1.94 valves


would they be a good improvement, i would probably do a cam swap at the same time, so i know that would help
Sell them to someone that doesn't know any better, or spend a lot of time and money on machining them. If you sell them, you could apply the proceeds to a better pair of factory castings like:

10088113 (aluminum, 58cc, 1.94/1.50 from the factory);

14014416/14014440, 58cc, 1.84/1.50 cast iron;

14102187, 58cc, 1.84/1.50 cast iron HO heads;


Or aftermarket castings, like World S/R 305s.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
TreDeClaw
Theoretical and Street Racing
11
06-22-2021 08:21 PM
sweet_87_iroc
Camaros for Sale
5
09-25-2015 10:01 PM
Dialed_In
Firebirds for Sale
2
08-20-2015 01:45 PM
TreDeClaw
Transmissions and Drivetrain
15
08-14-2015 06:58 PM



Quick Reply: double hump heads on a 305



All times are GMT -5. The time now is 01:06 PM.