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-   -   1985 305 vs. 1986 305 (https://67-72chevytrucks.com/vboard/showthread.php?t=595175)

jimboh247 09-02-2013 12:35 PM

1985 305 vs. 1986 305
 
Besides the 1 piece real seal, the center bolt valve covers, and the different bolt angle on the intake, is there any other differences between the '85 305, and the '86 305?

Jake Wade 09-02-2013 12:53 PM

Re: 1985 305 vs. 1986 305
 
86 should have the 1 pc rear main seal but the same perimeter valve cover as the 85. Intake bolt pattern the same also.

87 is when the change to centerbolt covers.

jimboh247 09-02-2013 01:07 PM

Re: 1985 305 vs. 1986 305
 
http://i173.photobucket.com/albums/w...Vj_600x450.jpg

The guy says it's an 86, out of a Camaro. But it has the center bolt heads, and what appears to be the old style intake bolt angle.

Whether it's an 86 or 87, is the cam the same between 85, 86 and 87? That is, if the 87 is not a roller cam.

INSIDIOUS '86 09-02-2013 01:18 PM

Re: 1985 305 vs. 1986 305
 
Depends on what 305 we are talking about. The truck 305 or passenger car 305
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jimboh247 09-04-2013 07:36 PM

Re: 1985 305 vs. 1986 305
 
Well, I pulled the intake, and it is at least an 87, due to the roller cam.
What I want to know:
Will 85 or earlier heads bolt on to the 87 block if I use the earlier intake?
Can I ditch the roller cam and go with a cam from an earlier (non-roller) motor?
All I really need is the short block.

Jake Wade 09-04-2013 08:45 PM

Re: 1985 305 vs. 1986 305
 
Yes to all your questions. I would take advantage of that roller ready block,myself

07XCSBZ71 09-04-2013 09:18 PM

Re: 1985 305 vs. 1986 305
 
You'll have to use the 86-up one piece rear main flywheel/flexplate. I agree with Jake, I would use the roller setup. Free upgrade.

jimboh247 09-04-2013 10:24 PM

Re: 1985 305 vs. 1986 305
 
Quote:

Originally Posted by 07XCSBZ71 (Post 6254055)
You'll have to use the 86-up one piece rear main flywheel/flexplate. I agree with Jake, I would use the roller setup. Free upgrade.

Thanks for the heads up on the flexplate. I was fixin' to toss it on the scrap pile.

I have a new flat tappet cam, but I guess I could sell it and get a roller cam. I'm going to pull the heads and oil pan to check everything inside out.

jimboh247 09-06-2013 09:59 AM

Re: 1985 305 vs. 1986 305
 
Another question:
Does the factory cam use a different cam gear on the distributor?

INSIDIOUS '86 09-06-2013 03:07 PM

Re: 1985 305 vs. 1986 305
 
Quote:

Originally Posted by jimboh247 (Post 6256301)
Another question:
Does the factory cam use a different cam gear on the distributor?

A flat tappet cam can take a normal iron distributor gear. Roller cams are steel and will eat through those quickly so you will have to get a melonized distributor gear to run
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