swapping cylinder heads

View previous topic View next topic Go down

swapping cylinder heads

Post by Bruisr on Mon May 27, 2013 3:39 pm

My sons 76 GMC sprint has a 305, both heads are cracked! Can I use a set of heads that the casting number claims they are for 307/350 engine. Trying to get it up an running for daily use, as cheaply as possible.
Engine casting #460777
Cracked heads #376450
Heads I'd like to install #3998993, they were free, and ready to bolt-on. I also have a used set of 350, will they work?
avatar
Bruisr
G3GM Member
G3GM Member

Street Cred : 8

Back to top Go down

Re: swapping cylinder heads

Post by 77mali on Mon May 27, 2013 5:00 pm

Heres a good read:
http://www.hotrodders.com/forum/what-u-think-3998993-sbc-heads-125251.html

Also, does he have a 4 or 2 bbl carb? 3998993 were cast for 4bbl set up, I believe.

I have 305 heads if you want them, just pay shipping & they're yours. They weigh about 50-55 lbs per box- would have to ship each individually. They look good & they ran good when I first got the car. What's your zip I can get a rate via US PO Parcel Post.

http://s1049.photobucket.com/user/77mali/library/Stuff%20for%20Sale?sort=6&page=1

(Intake is gone)
avatar
77mali
Donating Member
Donating Member

Street Cred : 62

Back to top Go down

Re: swapping cylinder heads

Post by Limey SE on Mon May 27, 2013 5:21 pm

77mali wrote:Heres a good read:
http://www.hotrodders.com/forum/what-u-think-3998993-sbc-heads-125251.html

Also, does he have a 4 or 2 bbl carb? 3998993 were cast for 4bbl set up, I believe.

I have 305 heads if you want them, just pay shipping & they're yours. They weigh about 50-55 lbs per box- would have to ship each individually. They look good & they ran good when I first got the car. What's your zip I can get a rate via US PO Parcel Post.

http://s1049.photobucket.com/user/77mali/library/Stuff%20for%20Sale?sort=6&page=1

(Intake is gone)

Go Fed Ex for the Heads the box is stronger and also is cheaper to send, I sent a pair of 455 heads for under 60 bucks To PA
avatar
Limey SE
Management
Management

Street Cred : 85

Back to top Go down

Re: swapping cylinder heads

Post by Joe73 on Mon May 27, 2013 5:40 pm

I'd check cylinder chamber sizes before switching. Alot of 305's came with real small chamber heads, something in the 58cc range. Most other small blocks came with 64cc-76cc ranges. More cc's will mean less compression and power. Most small blocks in our years are in the 76cc range. So going from 58cc (if you have them) to 76cc would be a big drop in power. Going from a 76cc head to a 64cc head, without any other changes, yields about a 1.5 drop in compression ratio.

Thats why some guys will take a stock small block and swap some 305 heads on it and maybe a cam. The extra compression will wake up a small block.

Just a thought.
avatar
Joe73
Donating Member
Donating Member

Street Cred : 65

Back to top Go down

Re: swapping cylinder heads

Post by Bruisr on Mon May 27, 2013 7:31 pm

77 Mali: I think I might have to take you up on that offer! My zip code is 85354. Let me know what you find out please.
avatar
Bruisr
G3GM Member
G3GM Member

Street Cred : 8

Back to top Go down

Re: swapping cylinder heads

Post by 77mali on Mon May 27, 2013 7:44 pm

Have to dig them out & get dimensions off the boxes. Will try to get in there asap & get weight also. Do you want the rockers as well?
avatar
77mali
Donating Member
Donating Member

Street Cred : 62

Back to top Go down

Re: swapping cylinder heads

Post by Limey SE on Mon May 27, 2013 7:46 pm

77mali wrote:Have to dig them out & get dimensions off the boxes. Will try to get in there asap & get weight also. Do you want the rockers as well?

Mali a tip on the boxes get them from UHAUL they are triple strength and mine I sent to PA survived the trip perfectly
avatar
Limey SE
Management
Management

Street Cred : 85

Back to top Go down

Re: swapping cylinder heads

Post by dynchel on Mon May 27, 2013 8:29 pm



Thats why some guys will take a stock small block and swap some 305 heads on it and maybe a cam. The extra compression will wake up a small block.

Just a thought.[/quote
that is the set up I have on my '74. I have some #416 ho heads from a 84 monte Carlo (58cc chamber) compared to the (76 cc chamber smoggers) on my original 350. This is a old circle track trick to run a "stock" class, but if you want to do block long burn outs this is the cheap route to go. I've read that they run out of steam at high rpms, but I've never had a problem. (I really don't run this engine to high rpm's very often) GoFast
avatar
dynchel
Donating Member
Donating Member

Street Cred : 40

Back to top Go down

Re: swapping cylinder heads

Post by Bruisr on Mon May 27, 2013 10:46 pm

77 Mali- You are the only option I have right now. If I did find a set of 305 heads(whatever they cost), I'd probably have to have them rebuilt and or inspected. Probably run me into the 4-500 range. My sons neglect is not gonna cost me that much! He is lucky I'm even doing the work! Yes I'll take the rockers Please! Thanks Mali.
avatar
Bruisr
G3GM Member
G3GM Member

Street Cred : 8

Back to top Go down

Re: swapping cylinder heads

Post by 77mali on Mon May 27, 2013 11:01 pm

Just sent you a PM...Will do my best to dig them out & get you the info as soon as possible.
avatar
77mali
Donating Member
Donating Member

Street Cred : 62

Back to top Go down

Re: swapping cylinder heads

Post by Bruisr on Mon May 27, 2013 11:05 pm

Thanks again!
avatar
Bruisr
G3GM Member
G3GM Member

Street Cred : 8

Back to top Go down

Re: swapping cylinder heads

Post by 77mali on Tue May 28, 2013 6:05 pm

They R dug out, will box them up tonight & try to get them weighed tomorrow to get you the shipping charges.
avatar
77mali
Donating Member
Donating Member

Street Cred : 62

Back to top Go down

Re: swapping cylinder heads

Post by Bruisr on Wed May 29, 2013 12:58 am

Good deal, Thanks!
avatar
Bruisr
G3GM Member
G3GM Member

Street Cred : 8

Back to top Go down

Re: swapping cylinder heads

Post by 77mali on Thu Jun 06, 2013 6:36 pm

Tracking says arrival on 6/5...can you confirm delivery? Did they arrive in good shape?



avatar
77mali
Donating Member
Donating Member

Street Cred : 62

Back to top Go down

Re: swapping cylinder heads

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum