Worth the effort to switch to E7 heads from my stock E5s?

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

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Nov 11, 2003

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Oct 27, 2004

#1

• Oct 27, 2004

• #1

I've got a buddy who's giving me some E7s that are just collecting dust in his garage....my car's still using the stock E5s ('85 motor)....would it be worth the pulling of the intake end everything and the price of gaskets and all that just to swap out for production-stock E7s? He said he's going to help me do a valve job on them but the lifters and springs will all still be factory installed/used. I'm looking for super cheap power gains, if any.

 

shttygtstang

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Jun 2, 2004

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Oct 27, 2004

#2

• Oct 27, 2004

• #2

sounds great but are you gunna have piston to valve clearnce.do the 85s have notched pistons

 

J

jd351

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Oct 27, 2004

#3

• Oct 27, 2004

• #3

Not sure if you have enough valve clearance, may need to notch pistons, and, I don't think there that much better to begin with. The valve size is the biggest (only) difference between the two if I remember correctly. IF, you need to notch the pistons then I would say not, it's not worth it, not unless you do a realy good job of porting or at least polishing the ports and a good three angle valve job.

 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

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Oct 28, 2004

#4

• Oct 28, 2004

• #4

The '85s are notched pistons, only the '86s came with flat tops. I don't think the valves are that huge that it would make a difference with a stock cam, as i'm pretty sure you can put GT40s on an '85 with no problem.

 

V

v8only

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Jul 3, 2003

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Oct 28, 2004

#5

• Oct 28, 2004

• #5

the e5's and e7's are very similar. the hp difference between the 87+ and the 85's is only 10-15, and I believe most of that is because of the efi. imo, you're not gonna notice a difference worth enough to yank them. Probably no seat of the pants difference, and maybe a tenth at the most. I'd port em, or get some gt40 heads.

 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end

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#6

• Oct 28, 2004

• #6

v8only said:

the e5's and e7's are very similar. the hp difference between the 87+ and the 85's is only 10-15, and I believe most of that is because of the efi. imo, you're not gonna notice a difference worth enough to yank them. Probably no seat of the pants difference, and maybe a tenth at the most. I'd port em, or get some gt40 heads.

Click to expand...

I was thinking the same thing, but since it looks like you've got a 4 eye and you're a bit knowledgeable, do you know if the cams are very different between the '85s and '87+'s? That might have something to do with the HP numbers too, but the '85s were rated at 210 and the '87s were 225...but i believe the EFI brought up the torque a bit more than the HP. I might just start working on porting them a bit and wait till i need a head gasket replaced.

 

V

v8only

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#7

• Oct 28, 2004

• #7

four eyed pride could answer the cam question a little better. i do know the 86-88 speed density cams are known to be the most aggressive, but not too sure on the 85 one. I would think it's not a whole lot different