Which heads for 521 in heavy street car?

Thinking about building a 521 for my Galaxie. Weighs 4247 with me in it. Currently has mild 460 with comp magnum 292 cam, stealth intake, lightly ported doves, zero decked with stock dove pistons, 950 Holley hp.
Wanting to build a 521 pump gas motor, going to stay hydraulic cam, flat tappet or roller. Car has a 3800 10" converter in it now. I'm pretty sure my headers are actually for a cobra jet head. Been looking at the TFS street heads or the 280cc AFR heads. Kind of wanting to use my stealth intake. Car currently runs 7.90 in the 1/8th. But I can still take it on road trips. I only have a 3.70 gear in it now. Not wanting to change that, seams to work pretty good on the highway.

PM sent

Or would scj's work better?

I would do scj or P51's . my pump gas 10:1 p51 headed motor went 6.70's on 91 octane c6, 3.50 gear at 3900lbs. but it has a solid roller.

wayne

dfree383 wrote:TFS streets would work fantastic IMO.

I'd do a pump gas 545 and tighten up that convertor

Love the thought!

64galaxie wrote:Thinking about building a 521 for my Galaxie. Weighs 4247 with me in it. Currently has mild 460 with comp magnum 292 cam, stealth intake, lightly ported doves, zero decked with stock dove pistons, 950 Holley hp.
Wanting to build a 521 pump gas motor, going to stay hydraulic cam, flat tappet or roller. Car has a 3800 10" converter in it now. I'm pretty sure my headers are actually for a cobra jet head. Been looking at the TFS street heads or the 280cc AFR heads. Kind of wanting to use my stealth intake. Car currently runs 7.90 in the 1/8th. But I can still take it on road trips. I only have a 3.70 gear in it now. Not wanting to change that, seams to work pretty good on the highway.

Sounds like a cool ride. I'm sure whatever you decide it will be a blast. Good luck!

Hi Brant, just something to think about. Your definately going to need a good 9 center if ya bring the 60ft down much either way ya go. Just thought it be good Idea to keep a eye opened for a used one till then to save some $$.

A bit OT but how is your hood clearance? Are you running a tear drop hood?

wayney wrote:I would do scj or P51's . my pump gas 10:1 p51 headed motor went 6.70's on 91 octane c6, 3.50 gear at 3900lbs. but it has a solid roller.

wayne

Just for giggles.... I plugged your 3900 lbs and a 6.75 1/8th mile E.T. into a Wallace Calculator and it determined your "pump gas 10:1 p51 headed motor" is producing 626 HP.

EDIT: That is right where Ford Motorsport claimed their 514*/521 would be rated - 625 HP (M-6007-D514*)

Colt Macara wrote:

wayney wrote:I would do scj or P51's . my pump gas 10:1 p51 headed motor went 6.70's on 91 octane c6, 3.50 gear at 3900lbs. but it has a solid roller.

wayne

Just for giggles.... I plugged your 3900 lbs and a 6.75 1/8th mile E.T. into a Wallace Calculator and it determined your "pump gas 10:1 p51 headed motor" is producing 626 HP.

EDIT: That is right where Ford Motorsport claimed their 514*/521 would be rated - 625 HP (M-6007-D514*)

I'm pretty sure it would pump a bit more than that on a dyno.  I run a true 3in turbo mufflers to keep it quiet not straight through and the converter is 900 rpm tight and geared for nitrous. it went 9.76 on a 190 shot through a plate system .

wayne

P.S. the short block is for sale, stepping up to an A460 block

wayney wrote:

Colt Macara wrote:

wayney wrote:I would do scj or P51's . my pump gas 10:1 p51 headed motor went 6.70's on 91 octane c6, 3.50 gear at 3900lbs. but it has a solid roller.

wayne

Just for giggles.... I plugged your 3900 lbs and a 6.75 1/8th mile E.T. into a Wallace Calculator and it determined your "pump gas 10:1 p51 headed motor" is producing 626 HP.

EDIT: That is right where Ford Motorsport claimed their 514*/521 would be rated - 625 HP (M-6007-D514*)

I'm pretty sure it would pump a bit more than that on a dyno.  I run a true 3in turbo mufflers to keep it quiet not straight through and the converter is 900 rpm tight and geared for nitrous. it went 9.76 on a 190 shot through a plate system .

wayne

P.S. the short block is for sale, stepping up to an A460 block

Using the same calculator, your 9.76 in the quarter is 829HP on the NOS. Take away 190 = 639. Within 14HP from your all motor 1/8th. The calculators are just a guesstimate, but pretty close..... just for fun. How big are you going with the new A460?

Colt Macara wrote:

wayney wrote:

Colt Macara wrote:

wayney wrote:I would do scj or P51's . my pump gas 10:1 p51 headed motor went 6.70's on 91 octane c6, 3.50 gear at 3900lbs. but it has a solid roller.

wayne

Just for giggles.... I plugged your 3900 lbs and a 6.75 1/8th mile E.T. into a Wallace Calculator and it determined your "pump gas 10:1 p51 headed motor" is producing 626 HP.

EDIT: That is right where Ford Motorsport claimed their 514*/521 would be rated - 625 HP (M-6007-D514*)

I'm pretty sure it would pump a bit more than that on a dyno.  I run a true 3in turbo mufflers to keep it quiet not straight through and the converter is 900 rpm tight and geared for nitrous. it went 9.76 on a 190 shot through a plate system .

wayne

P.S. the short block is for sale, stepping up to an A460 block

Using the same calculator, your 9.76 in the quarter is 829HP on the NOS. Take away 190 = 639. Within 14HP from your all motor 1/8th. The calculators are just a guesstimate, but pretty close..... just for fun. How big are you going with the new A460?

plan is 572 on new motor, also switching to A460 heads still pump gas drive able 11:1 cr.

wayne