Hi everyone,

I am just wondering if a set of Alloy SVO heads will bolt straight up to my AU 220.

They have a couple of part numbers on them.

Y 808 (or SOS)
F8ZM
0049

Are these GT40X or GT40Y heads?

Will they bolt up to my hurricane headers and explorer manifold?

Do they offer a big improvement over the YT GT40P heads?

Also will the Yella Terra roller rockers that are on my GT40Ps bolt straight onto theses?

Thanks

Sorry the marking is Y302

https://fordperformanceracingparts.com/ ... Field=1771

that might help

They are an olloy version of the GT40. NOT GT40P. while they will be direct bolt on, you will need to change headers as the plug angle is different. same plug angle as E series.

Interesting reading a few links. Lower compression however significantly more advance. Also worth doing valve job on beforehand and they'll be as good as 40's or 40p's

However you have a 220. They have a lot of work done on them so you may in fact go backward. The two advantages you will see are weight (handling and steering) and cooling

The advantage in the weight saving will be negligible. a few kilos at best.

Better off getting a set of aftermarket heads like AFR or twisted wedges. Y302's are a good upgrade on an E series, They are on par with GT40 or 40p's.

Side note.
GT40's and GT40P's. are essentially the same thing, its only the plug angle that sets them apart.
Y302's are pretty much the same as GT40X or Allow versions of their respective GT40 and GT40P Iron cousins.

Yep you can get them opened out, but the money you spend doing so.. Just go straight to an aftermarket item that will outflow them.

Personally, I run Edelbrock E-Streets that have been ported and had the valve gear replaced/Upgraded, Isky Valve springs, Jesel Shaft mount rockers , manley valves.

There are plenty of better options than stock gear for very little extra money. Just take your time, keep your eye out and ask plenty of questions

I also run modified e-streets on my 347 sbf's. What p/n isky spring do you run? Do you use the fox-lake e-streets? 3 months ago I bought up most of the stocks of e-streets in NZ that came in when the NZ$ was high against the US$

I wouldn't waste my money on Y302/Y303 heads. They only flow about 210cfm. That's rubbish for an aftermarket head. Untouched GT40P's flow 195cfm, the YT GT40P's in the 220/250kw AU falcons are probably 5-10cfm better