2/18/2026
CYLINDER HEADS
NEWS 2/18/2026
BY THE END OF THE FIRST WEEK OF FEBURARY -
The Rocket-428 core-box was delivered and the cores were started.
The Cope and Drag patterns were picked up by the foundry at my place.
The foundry must wait for the cores to be finished
then casting can be put into the que.
The machine shop has been informed and is ready to get started.
time frame is too loose to spec yet.
Deposit invoices have been mailed or emailed
to each person on the list.
Down payment/deposits are now due.
IF YOU NEED TO CHARGE THE DEPOSIT,
GO DOWN TO BOTTOM OF THIS PAGE AND CLICK ON FLAG.
If you are wavering
here are couple important considerations:
1: Order one now,
even if you're not sure about needing it.
The pricing will never get lower.
If you decide to sell your investment, you should
get your money back plus some.
2: Enjoy the same power
& chambers as my Lion Speed Head IV.
3: The Rocket-428
is quite street able and
made ready for hill climbs.
4: Free Shipping if you move quickly.
5: While it is possible
that a few finished
heads left may be left over,
it has been my experience since 1998,
that we are usually completely
sold out by shipping day.
6: Don't take a chance.
If this is the direction you want to take,
order now!
BY THE END OF THE FIRST WEEK OF FEBURARY -
The Rocket-428 core-box was delivered and the cores were started.
The Cope and Drag patterns were picked up by the foundry at my place.
The foundry must wait for the cores to be finished
then casting can be put into the que.
The machine shop has been informed and is ready to get started.
time frame is too loose to spec yet.
Deposit invoices have been mailed or emailed
to each person on the list.
Down payment/deposits are now due.
IF YOU NEED TO CHARGE THE DEPOSIT,
GO DOWN TO BOTTOM OF THIS PAGE AND CLICK ON FLAG.
If you are wavering
here are couple important considerations:
1: Order one now,
even if you're not sure about needing it.
The pricing will never get lower.
If you decide to sell your investment, you should
get your money back plus some.
2: Enjoy the same power
& chambers as my Lion Speed Head IV.
3: The Rocket-428
is quite street able and
made ready for hill climbs.
4: Free Shipping if you move quickly.
5: While it is possible
that a few finished
heads left may be left over,
it has been my experience since 1998,
that we are usually completely
sold out by shipping day.
6: Don't take a chance.
If this is the direction you want to take,
order now!
DEPOSIT DUE NOW
Invoices for $400 Deposit scheduled to email Friday 2/6/2026
The Rocket-428 High Compression Cylinder head
Cast Aluminum 356-T6,
7:1 Compression Ratio (140-cc)
All Heads Are Dual Plug
Invoices for $400 Deposit scheduled to email Friday 2/6/2026
The Rocket-428 High Compression Cylinder head
Cast Aluminum 356-T6,
7:1 Compression Ratio (140-cc)
All Heads Are Dual Plug
This head wins hill climbs!
THE ROCKET 428 HEAD PROJECT IS A GO.
THE ROCKET 428 HEAD PROJECT IS A GO.
ORDER NOW FOR FUTURE DELIVERY
Names that do not follow through with a deposit
within 15 days of invoice will be removed
from the list and head numbers will be adjusted.
The casting and machine time frame is usually 4-5 months.
THIS PRICE WILL HOLD UNTIL MARCH 1ST
$1200 & FREE SHIPPING
(+ $40 USA SHIPPING
FOR ORDERS AFTER MARCH 1
if there are any left)
TO GET A BRAND NEW
ROCKET 428 SPEED HEAD
YOU MUST MAKE A
$400 DEPOSIT
Deposits are non-refundable once casting order has
been made. Full refund if we cannot produce.
All cost and time suggestion are approximate
and could change as we move forward.
ESTIMATED DELIVERY IS JUNE-ISH (+-)
PAYMENT
We accept Personal Check, Cashier’s Check, and Money Orders by mail.
MAKE OUT AND MAIL TO:
YAPP STUDIOS INC.
3860 Cain Run Rd
Batavia OH 45103
CREDIT CARDS & PAYPAL: we charge a 6% handling fee on the deposit ($24)
and on the balance due ($48). To pay with CARDS scroll DOWN to bottom of page.
513-724-9000
[email protected]
Names that do not follow through with a deposit
within 15 days of invoice will be removed
from the list and head numbers will be adjusted.
The casting and machine time frame is usually 4-5 months.
THIS PRICE WILL HOLD UNTIL MARCH 1ST
$1200 & FREE SHIPPING
(+ $40 USA SHIPPING
FOR ORDERS AFTER MARCH 1
if there are any left)
TO GET A BRAND NEW
ROCKET 428 SPEED HEAD
YOU MUST MAKE A
$400 DEPOSIT
Deposits are non-refundable once casting order has
been made. Full refund if we cannot produce.
All cost and time suggestion are approximate
and could change as we move forward.
ESTIMATED DELIVERY IS JUNE-ISH (+-)
PAYMENT
We accept Personal Check, Cashier’s Check, and Money Orders by mail.
MAKE OUT AND MAIL TO:
YAPP STUDIOS INC.
3860 Cain Run Rd
Batavia OH 45103
CREDIT CARDS & PAYPAL: we charge a 6% handling fee on the deposit ($24)
and on the balance due ($48). To pay with CARDS scroll DOWN to bottom of page.
513-724-9000
[email protected]
ROCKET-428 CYLINDER HEAD
356-T6 Aluminum, 7:1 CR
all castings are 8 Spark plugs
FOR THOSE NEEDING A FOUR (4) PLUG HEAD WE HAVE "PLUG-SEALS"
The Rocket's combustion chambers are a match of our very successful Lion Speed Head IV.
The thick walls hold heat steady for even firing and extra metal is available to those that want to reshape to their own designs. The spark plug positions are designed for maximum flame front and have proven power on the dyno. Plugs on the left have more power.
The thick walls hold heat steady for even firing and extra metal is available to those that want to reshape to their own designs. The spark plug positions are designed for maximum flame front and have proven power on the dyno. Plugs on the left have more power.
The foundry and machinist men helping me produce this 2026 production run are the same who have done our Rocket-428 in the last run. They know my need for precision and have proven to me that they will do a fantastic Made-in-USA-job.
for Credit Card sales
of Rocket Cylinder Heads
click the USA map above
of Rocket Cylinder Heads
click the USA map above