will stock explorer gt-40 heads clear 89 flat top stock forged pistons

blk8950

New Member
Mar 28, 2008
3
0
0
i buying a 89 rebuilt short block with the 89 completly flat forged pistons do the stock explorer gt-40 heads have at least a 64 cc size
help please asap
 
  • Sponsors (?)


LiquidGT

Member
Oct 8, 2007
368
0
16
Near STL hell
The heads should fit fine, the type of cam is the main thing to question with clearances.

When I compared my Explorer and forged Mustang short block, the Explorer pistons were flat and the Mustang pistons had a slight dish to them.

I believe the 64cc Explorer heads plus the Mustang forged pistions will give you lower compression than a stock 5.0 Mustang (9:1).
 

NIKwoaC

中國製造
10 Year Member
Oct 31, 2006
5,500
914
214
Chengdu Province
Three things:

1.0 Use clear, thorough thought patterns in your typing, along with coherent grammar. We can answer your questions better if we better know what you are asking.

2.0 The only year Mustangs used flattop pistons was 1986. All other years have valve relief notches in the piston surface. If your block has flattop pistons, it is NOT from a 1989 Mustang. If it does have relief notches, the Explorer heads will bolt on.

3.0 I believe Explorer GT-40s have a 64-66 cc chamber while GT-40Ps have a 59-60 cc chamber.
 

Fast63

New Member
Sep 20, 2007
717
0
0
just because a piston has valve reliefs doesn't mean it isn't a flat top piston. The 87-93 pistons I think have a small dish in the center as well as the valve reliefs. My 85 pistons were flat tops with valve reliefs and no dish.
 

BlownFiveLiter

have car, will race....wait, it doesn't run
15 Year Member
Nov 29, 1999
3,134
18
108
Chicagoland
blk8950 said:
i believe the cam is 208/216 .530int .530exh

I'm more than willing to bet that cam won't clear with .530 lift. Yes there are other factors involved in whether a cam will clear, or not, but that's an awful lot of lift to put in a stock shortblock.
 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end
15 Year Member
Nov 11, 2003
6,945
1,598
223
Northern KY
I got in this debate over on 4eyedpride about the flat top vs. dish thing, and i actually just looked at my buddy's '87 short block in his garage and there actually is a very very slight dish in the middle, maybe only 1/32 deep. I too thought they were ALL flat top, with the '86 being without valve reliefs but i was wrong. Even still, i highly doubt that little dish has any effect whatsoever on PTV clearance.
 

Mr. Rustypwnz

Advanced Member
Jun 1, 2005
1,761
63
69
indianapolis/ valdosta ga
well to answer the original q' yes they will work with that cam and heads, i had around a .520 lift cam in my other car and it worked fine, good heads for the money, and when ported they really wake up, im about to fire my ported p head combo up tomorrow, so it should be fun!!
 

85_SS_302_Coupe

it sucks (I know) to be on the receiving end
15 Year Member
Nov 11, 2003
6,945
1,598
223
Northern KY
What i've always heard is that around .550 lift is the limit, but of course do a PTV clearance check to be sure. Also if you mill the heads of course that changes things.