Got my GT40P heads, should I have machine work done, new springs?

QuantumMotorsports · 07-28-2003, 09:34 AM

I got a set of GT40P heads from this guy locally who gets 20 or 30 sets at a time from a dealer (he says they come off of warranteed motors) They look fine, probably have under 50k miles on them. Do you guys think I should take them to the machine shop that did my short block for a valve job and new seals? They want $150 to vat the heads, magnaflux, check the guides, 3 angle valve job, machine them flat, and new seals. And with a .534 lift cam, I'm not sure if the stock valves can handle it. I think I can get a Comp cams set for like $80, single springs that will take that lift. What do you guys think? should I do that, or just bolt them on?

bigred90gt · 07-28-2003, 11:04 AM

Quote:

Originally posted by QuantumMotorsports
I got a set of GT40P heads from this guy locally who gets 20 or 30 sets at a time from a dealer (he says they come off of warranteed motors) They look fine, probably have under 50k miles on them. Do you guys think I should take them to the machine shop that did my short block for a valve job and new seals? They want $150 to vat the heads, magnaflux, check the guides, 3 angle valve job, machine them flat, and new seals. And with a .534 lift cam, I'm not sure if the stock valves can handle it. I think I can get a Comp cams set for like $80, single springs that will take that lift. What do you guys think? should I do that, or just bolt them on?

I'd definately go for it. Sounds like a pretty decent price. Will this guy sell another set of these heads? I have been looking for a good deal on heads. If you dont mind, see what you can find out and let me know. Thanks in advance.

Caymon

QuantumMotorsports · 07-28-2003, 02:58 PM

I can get you a set for $200. I'll send you some pics of mine the way they came. They are complete with stock valves and rockers. I'll see about shipping if you want or you can come up to Norman and pick them up. If you want to, email me mblack@ou.edu If anyone else is interested, I can get you a set at the same price.

Coupe50h · 07-28-2003, 07:50 PM

well to answer you question, yes you need springs, my heads came off an explorer, non p heads, but the explorer springs will not handle the lift for long, they might work for a while, read some old post about my "valve float" threads, my motor would not rev past 5500 rpm's (i run the e-cam), i bought some comp springs 70$ i can give you a part # will have to look for it, but fiveohpatrol recomended them, my car now pulls to the redline and gained 2 mph in the 1/4, do it before the heads go on, you'll be glad,
also, always magnaflux used heads, you dont know if they got real hot at one time or not.
p.s, i used my stock retainer with my springs, no problems yet (knocks on wood)

chiaronate · 08-10-2003, 05:50 PM

hey Coupe5oh, looks like your running the same set-up i was thinking about running. only difference is i think i'll get the gt40p heads and 3.73's. any idea how much horsepower and torque your making and what rpm's? i like how the e303 toruqe peaks at 2500 rpm, similar to the 1993-1997 lt1's. how far does the torque curve go? those are nice track times!

Coupe50h · 08-10-2003, 09:07 PM

Thanx alot, i do think with a dyno pull/tune or two, i could make some more power, i would like to think it's making close to 295 lbs of torque to the rear wheels, but only a dyno will tell, we have a few dynos in town, i'll let you know, I like the e-cam too, as far as the torque, my car pulls good at low rpms, about 1500 rpms i can slip my clutch (clutch is worn/thrashed/burnt) but it feels like it slips as the torque starts to peak (lower rpms).
With a new clutch, 12.90's @ 106 is what im expecting next time out, in some cooler weather.

glenn95gt · 08-10-2003, 11:44 PM

Yes you should have it machined, and the springs should be repalced as well. I have a set of AFR double valve springs I can sell you for $50. It will handle up to a .550* lift. Let me know.

07-28-2003, 09:34 AM	#1
QuantumMotorsports Registered Member Join Date: Jul 2000 Location: Norman, Oklahoma, USA Posts: 597	Got my GT40P heads, should I have machine work done, new springs? I got a set of GT40P heads from this guy locally who gets 20 or 30 sets at a time from a dealer (he says they come off of warranteed motors) They look fine, probably have under 50k miles on them. Do you guys think I should take them to the machine shop that did my short block for a valve job and new seals? They want $150 to vat the heads, magnaflux, check the guides, 3 angle valve job, machine them flat, and new seals. And with a .534 lift cam, I'm not sure if the stock valves can handle it. I think I can get a Comp cams set for like $80, single springs that will take that lift. What do you guys think? should I do that, or just bolt them on? __________________ Michael Black QuantumMotorsports Norman, OK 1984 LX Hatch 306 w/ TRW forged flat toppers, Comp Cams Magnum 292H, GT40P heads w/ 3 angle valve job, .550 lift springs, Angus Racing Roller Rockers, Weiand Stealth Intake, Holley 4150 650cfm carb, MAC 1 5/8 Long Tubes, Single Chamber Flowmasters, 91' T5 w/ Pro 5.0 shifter, Turbo Coupe 8.8 Rear w/ 3.55 gears, QA1 Motorsports tubular K member, no interior except steering wheel and seat. Coming soon: 6 or 8 point cage, Fuel Cell, Weld Draglites

07-28-2003, 02:58 PM	#3
QuantumMotorsports Registered Member Join Date: Jul 2000 Location: Norman, Oklahoma, USA Posts: 597	I can get you a set for $200. I'll send you some pics of mine the way they came. They are complete with stock valves and rockers. I'll see about shipping if you want or you can come up to Norman and pick them up. If you want to, email me mblack@ou.edu If anyone else is interested, I can get you a set at the same price. __________________ Michael Black QuantumMotorsports Norman, OK 1984 LX Hatch 306 w/ TRW forged flat toppers, Comp Cams Magnum 292H, GT40P heads w/ 3 angle valve job, .550 lift springs, Angus Racing Roller Rockers, Weiand Stealth Intake, Holley 4150 650cfm carb, MAC 1 5/8 Long Tubes, Single Chamber Flowmasters, 91' T5 w/ Pro 5.0 shifter, Turbo Coupe 8.8 Rear w/ 3.55 gears, QA1 Motorsports tubular K member, no interior except steering wheel and seat. Coming soon: 6 or 8 point cage, Fuel Cell, Weld Draglites

07-28-2003, 07:50 PM	#4
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	well to answer you question, yes you need springs, my heads came off an explorer, non p heads, but the explorer springs will not handle the lift for long, they might work for a while, read some old post about my "valve float" threads, my motor would not rev past 5500 rpm's (i run the e-cam), i bought some comp springs 70$ i can give you a part # will have to look for it, but fiveohpatrol recomended them, my car now pulls to the redline and gained 2 mph in the 1/4, do it before the heads go on, you'll be glad, also, always magnaflux used heads, you dont know if they got real hot at one time or not. p.s, i used my stock retainer with my springs, no problems yet (knocks on wood) __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

08-10-2003, 09:07 PM	#6
Coupe50h Registered Member Join Date: Aug 2002 Location: SanAntonio, Tx Posts: 957	Thanx alot, i do think with a dyno pull/tune or two, i could make some more power, i would like to think it's making close to 295 lbs of torque to the rear wheels, but only a dyno will tell, we have a few dynos in town, i'll let you know, I like the e-cam too, as far as the torque, my car pulls good at low rpms, about 1500 rpms i can slip my clutch (clutch is worn/thrashed/burnt) but it feels like it slips as the torque starts to peak (lower rpms). With a new clutch, 12.90's @ 106 is what im expecting next time out, in some cooler weather. __________________ X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's. race weight 3,160 12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear 13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear

08-10-2003, 11:44 PM	#7
glenn95gt Registered Member Join Date: Jun 2003 Location: Bay Area, Ca Posts: 86	Yes you should have it machined, and the springs should be repalced as well. I have a set of AFR double valve springs I can sell you for $50. It will handle up to a .550* lift. Let me know. __________________ StAnGaHoLiC!!! 1995 GT S-Trimmed 306, with H/C/I, and some other stuff. It just sounds fast. My Car

08-10-2003, 05:50 PM	#5
chiaronate Registered Member Join Date: Jul 2002 Location: watervliet, ny Posts: 105	hey Coupe5oh, looks like your running the same set-up i was thinking about running. only difference is i think i'll get the gt40p heads and 3.73's. any idea how much horsepower and torque your making and what rpm's? i like how the e303 toruqe peaks at 2500 rpm, similar to the 1993-1997 lt1's. how far does the torque curve go? those are nice track times!

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