Olds 307 head question

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TURNA

TURNA

Geezer
Jul 24, 2009
9,430
113
Socialist NY
Will 80-84 307 (5A) heads fit an 86 (7A) engine ?

I am pretty sure you can but I wait for the Olds experts.



Thanks!
 
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olds307 and 403

olds307 and 403

Geezer
Oct 14, 2008
5,330
113
Melville,Saskatchewan
Yes, what are you looking to do, improve performance? Everything should switch over except the intake being small port. As you know, you need the A4, Performer or RPM. You may experience a slight drop in compression, I would mill them at least .010" or even .020". The early heads are supposedly 3cc bigger and you are already at 7.9 to 1 compression. You are off the computer, correct? That makes a huge difference on swirl port Y motors, very lean and 60+ degrees part throttle timing. Of course, better springs, 350 valves, bowl hog and blending work are also a good idea. It really depends on your end goal. You will also need a cam swap at that point and it snow balls from there. I would also do a timing set, the stock sets have the nylon coated cam gear.
 
TURNA

TURNA

Geezer
Jul 24, 2009
9,430
113
Socialist NY
Just want it to breath better I would mill them then port them slightly.

Yes computer system is gone, just doing that woke this car up incredibly.

Timing chain set and oil pump is new. I should have cammed it then. But was just trying to get it back together so I could enjoy it a little before winter got here........

Nope that didn't work out...............one early October Monday 70....Tuesday 30..........WTF?!?!?!?!?
 
olds307 and 403

olds307 and 403

Geezer
Oct 14, 2008
5,330
113
Melville,Saskatchewan
I hear you, I hate cars being in pieces. The only ones off the shelf, being a roller cam and stock rocker arms, would be the Comp XE262HR or the Lunati High Efficiency 20420504. Neither is cheap but lifters can be reused. A Vin 9 roller cam is also a slight upgrade, if you can find one. The 5A heads should help a bit, especially if work is done to them.
 
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TURNA

TURNA

Geezer
Jul 24, 2009
9,430
113
Socialist NY
Great thank you!!
 
TURNA

TURNA

Geezer
Jul 24, 2009
9,430
113
Socialist NY
Did a search on summit didn't see the Comp one.
 
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