 |
|
| Non Pontiac Motors in Pontiacs includes factory 403,305,350 Chevy, Buick V6, Also Pontiac Motors in non-Pontiacs! |
| Reply |
|
|
Thread Tools | Display Modes |
|
#1
10-05-2005, 02:18 PM
|
|||
|
|||
Chevy inline 6 swap help please
Hey Guys,
My son's 76 Firebird STR8 6 blew and the head cracked. We're trying to do this ourselves, we have a hoist and engine stand, and are taking the old out. We bought an 81 inline 6, but after it was dropped off and we are looking at it closer we see it's not designed the same. This one has alot of tubing coming out of the valve cover, and it has a Rodchester Varijet II on it rather than a Monojet....it also has two exhuasts, one next to the other, not the single the orig engine had. The linkage for the carb is all different as will be the exhaust...everything else looks like it'll fit in fine. The intake and exhaust heads are different, seperate, but totally different design than the regular head that was original. So we can't use the intake, exhaust, or carb off the orig. Here's our questions, we're at a complete stop now and need some advice... 1. Is this 81 Chevy/GMC 6 better than the reg 250 that was in there?...being the carb is a little bigger, two exhaust, etc) 2. Should we go with this or look for an early 70-76 inline 6?....if we do, is there a linkage adapter we can use to change the linkage? 3. There is a bunch of tubing (smog?) stuff on the valve cover (it's a 5 bolt, as opposed to the orig 3 bolt on side away from carb), can this stuff just be pulled off? We sure would appreciate any help anyone can give us as we're kinda stumped at this point....don't know whether to try and put this 81 in and figure out how to get the linkage and exhaust to work...or should we look longer for a 71-76 and try and sell the 81? Thanks!
__________________
Time to put another Pontiac back on the road! |
|
#2
10-05-2005, 02:22 PM
|
||||
|
||||
|
"but after it was dropped off and we are looking at it closer we see it's not designed the same"
Call them back, tell them to pick up the wrong engine and bring the correct one or your money back. Be lots easier.
__________________
Steve Yea, I know, the heads suck! 2005 Cordova Q16 Winner! 2005 Norwalk Sat Top ET Winner! |
|
#3
10-05-2005, 02:33 PM
|
|||
|
|||
|
Hey Slow....
Well, we tried that...it's an individual, and it's a done deal, no going back... ....yeah, we kinda blew it, but, it isn't as bad as it could have been...the engine was only $200...not that that isn't a healthy chunk of greenbacks now...but, the deal's over...yeah, he "should" take it back, but won't.... ...it was delivered last night around 10-10:30 pm....we really are at fault, no one to blame but myself, so I'm gonna bite it so my son doesn't have to work 3 more months to save it back up...but money is very tight....I wish he would take it back...he has no other engines...and we did ask specificlly if it was in integral head or not, did explain that we had a 76 6 being replaced and wanted to use parts from it, etc......classic case of noobs basically buying the wrong thing....but, still in the same spot....what's the best course of action?....would trying to work with this be throwing more bad money at it?
__________________
Time to put another Pontiac back on the road! |
|
#4
10-05-2005, 03:59 PM
|
||||
|
||||
|
Can you take pictures? It would be easier to figure out if you could take a picture of each one.
__________________
Steve Yea, I know, the heads suck! 2005 Cordova Q16 Winner! 2005 Norwalk Sat Top ET Winner! |
|
#5
10-05-2005, 04:06 PM
|
|||
|
|||
|
Yup...can do that!...I'll get some of both engines when I get home from work (about 3-4 hours from now)...
Thanks Slow!
__________________
Time to put another Pontiac back on the road! |
|
#6
10-06-2005, 12:10 AM
|
||||
|
||||
|
Chevy went to a two piece head around 1980 and every one I every saw had problems. It's been a long time, but I think they were notorious for blowing head gaskets or cracking.
I use to build 250's and they are the best way to go. Clifford Industries use to make headers, aluminum intakes, and other high performance parts for the old inlines. Not sure if they're still around though. There's nothing quite like the sound of a 250 straight 6 with a .583 lift solid cam rumbling through a set of header muflers.  Anyway, find an older inline 6 or just get another head. With a good fresh engine, you'll get good power and great gas milage. |
|
#7
10-06-2005, 02:02 AM
|
||||
|
||||
|
Probably a dumb question- can't you sell the '81 engine to pay for buying a head for your '76?
|
|
#8
10-06-2005, 08:36 AM
|
|||
|
|||
|
What you have is known as "integral" headed 250. The intake/exhaust is "integral" with the head. The earlier engines have separate intake and exhaust manifolds. They ARE notorious for cracking, and exhaust manifolds fall apart regularly.
The only REAL difference between them ("early" and "late") is the head and manifolding. The short block is pretty much the same. Using a head from any Chevy or Pontiac application from previous years will "work". The 194 head has smaller chambers, so watch static compression. 230 and 250 heads (as well as 292, HD truck) are much the same. The '73-'76 models have "hardened" exhaust seats. This is needed for the catalyst to work correctly (operating temperature must remain higher). I would try to locate the correct head. It should be easier than any other approach. Jim |
| Reply |
|
|
The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.
Linear Mode
