1.7 rockers with GT-40 P heads

jruppert · 09-11-2002, 10:03 PM

I have a '94 GT with a set of GT-40 P heads and an E-303 cam. I want to add a set of Crane 1.7 rockers. Will this work alright? I wasnt sure if I needed to modify the valve cover. I hear some people having to do this. Also, will it clear the pistons even though they are notched?

Dark_5.0 · 09-11-2002, 10:19 PM

You shouldnt have any clearance problems. Most people say you can reuse the stock valve covers if you remove the baffles and grind a little.

If you get tall valve covers you end up needing a phenolic spacer so your intake can clear the valve covers.

Good luck,

fiveohpatrol · 09-11-2002, 10:26 PM

Thats cutting the piston to valve clearance pretty tight. I would personally use the E303 with 1.6's

Also, I've heard of people having valve float problems when using 1.7's on the P heads, and resolving the issue by shimming the valve spring, not sure on the thickness shim though.

jruppert · 09-11-2002, 11:04 PM

I was doing some reading and I forgot that the '94-'95 Cobra had GT-40 heads. They also used a 1.7 roller rocker. Now I know that they didnt use anything like the E-303 cam or that they werent GT-40 P heads. I dont know exactly what the difference is between the GT-40 and the P heads.

93GTDIN · 09-11-2002, 11:51 PM

P-heads were on the explorer V8. They make a stout 245 horses when coupled with the explorer intake.

tireburner163 · 09-12-2002, 10:40 AM

DO NOT RUN GT-40P's with 1.7 RR's!!!!!!!!!!!!!!! Not unless you've got aftermarket valve springs. The stock ones bind after .500 lift. Even if did have aftermarket springs, flow falls off after .500 lift anyway, just throw on a set of 1.6 RR's.

93GTDIN you can lay down a lot more than 245hp with GT-40P heads, CCM's GT-40P crate motor with the stage 1 port lays down 320hp.

jruppert · 09-12-2002, 11:27 AM

The way my set up now is, GT-40 P heads (ported and polished), E-303 cam, Edelbrock upper and lower, 70mm t-body, 77 pro-m, 24lb injectors, custom chip (to help run the cam), king cobra clutch, tremec tko, aluminum driveshaft, 3.73 gears. So for my best is 13.4@106 I can't hook up worth a crap in 1st. I suppose I need better tires and suspension parts.

93GTDIN · 09-12-2002, 07:50 PM

i was referring to a stock explorer motor

1989GT · 09-13-2002, 10:54 PM

I'm not sure I'd run 1.7's with the E303. I run 1.72's with a B cam but that's a little different. The combo's in the sig. And I might add very little traction on drag radials.

09-11-2002, 10:03 PM	#1
jruppert Registered Member Join Date: Jul 2001 Location: Reed City Mi Posts: 106	1.7 rockers with GT-40 P heads I have a '94 GT with a set of GT-40 P heads and an E-303 cam. I want to add a set of Crane 1.7 rockers. Will this work alright? I wasnt sure if I needed to modify the valve cover. I hear some people having to do this. Also, will it clear the pistons even though they are notched?

09-11-2002, 10:19 PM	#2
Dark_5.0 Registered Member Join Date: Apr 2001 Location: Staging lane Posts: 4,337	You shouldnt have any clearance problems. Most people say you can reuse the stock valve covers if you remove the baffles and grind a little. If you get tall valve covers you end up needing a phenolic spacer so your intake can clear the valve covers. Good luck, __________________ 92' LX-Big brakes, Lots and lots of suspension, GT40X heads, Ported cobra intake, stock cam, Vortech SC trim. 00' Lightning-Stock 88'CRX-13 second ego killer

09-11-2002, 10:26 PM	#3
fiveohpatrol I'd rather be basketweaving Join Date: Feb 2000 Location: Indianapolis Posts: 2,551	Thats cutting the piston to valve clearance pretty tight. I would personally use the E303 with 1.6's Also, I've heard of people having valve float problems when using 1.7's on the P heads, and resolving the issue by shimming the valve spring, not sure on the thickness shim though. __________________ NMRA O/C 9516 NA pumpgas stickshift 347 10.65@125.6, 6.73@100, 1.41 60ft

09-11-2002, 11:51 PM	#5
93GTDIN Registered Member Join Date: Jan 2001 Location: Live music capital of the world, TX Posts: 324	P-heads were on the explorer V8. They make a stout 245 horses when coupled with the explorer intake. __________________ 96 Cobra - a bit too stock. 14.0 @ 101

09-12-2002, 10:40 AM	#6
tireburner163 It's a lot like a race car Join Date: Aug 2000 Location: Meridian, MS Posts: 4,130	DO NOT RUN GT-40P's with 1.7 RR's!!!!!!!!!!!!!!! Not unless you've got aftermarket valve springs. The stock ones bind after .500 lift. Even if did have aftermarket springs, flow falls off after .500 lift anyway, just throw on a set of 1.6 RR's. 93GTDIN you can lay down a lot more than 245hp with GT-40P heads, CCM's GT-40P crate motor with the stage 1 port lays down 320hp. __________________ 1987 Buick T-type 1998 HD Electra Elide

09-11-2002, 11:04 PM	#4
jruppert Registered Member Join Date: Jul 2001 Location: Reed City Mi Posts: 106	I was doing some reading and I forgot that the '94-'95 Cobra had GT-40 heads. They also used a 1.7 roller rocker. Now I know that they didnt use anything like the E-303 cam or that they werent GT-40 P heads. I dont know exactly what the difference is between the GT-40 and the P heads.

09-12-2002, 11:27 AM	#7
jruppert Registered Member Join Date: Jul 2001 Location: Reed City Mi Posts: 106	The way my set up now is, GT-40 P heads (ported and polished), E-303 cam, Edelbrock upper and lower, 70mm t-body, 77 pro-m, 24lb injectors, custom chip (to help run the cam), king cobra clutch, tremec tko, aluminum driveshaft, 3.73 gears. So for my best is 13.4@106 I can't hook up worth a crap in 1st. I suppose I need better tires and suspension parts.

09-12-2002, 07:50 PM	#8
93GTDIN Registered Member Join Date: Jan 2001 Location: Live music capital of the world, TX Posts: 324	i was referring to a stock explorer motor __________________ 96 Cobra - a bit too stock. 14.0 @ 101

09-13-2002, 10:54 PM	#9
1989GT Registered Member Join Date: Apr 1999 Location: Cincinnati,OH Posts: 1,511	I'm not sure I'd run 1.7's with the E303. I run 1.72's with a B cam but that's a little different. The combo's in the sig. And I might add very little traction on drag radials. __________________ 89GT,Pro-Bullet 306, H/C/I and a bunch of other stuff. Sold 00GT, Vortech S-Trim, Steeda Boost Pipe, C&L intake, Mac off-road H-pipe, Flowmasters, B&M Ripper shifter, Eibach Sportline springs, Koni Struts/shocks, MM full length subframe connectors, Cobra brakes, 3.73's. My Car Domain Page

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