The Boss 427 Ford Should Have Built

“Clevor” The Perfect Cleveland & Windsor Engine Build

By Ron Ceridono

For many automobile racing fans some of the most unique series of events were the Sports Car Club of America (SCCA) Trans-Am races that began in 1966. Despite the name of the sponsoring body the real stars of the show weren’t imported sports cars, rather it was the made in the USA “pony” cars in the production that got everyone’s attention. The sight and sound of these cars battling door to door sparked intense brand loyalty, something that was not lost on the manufacturers. And there’s no question that the “win on Sunday, sell on Monday” strategy served them well.

- Advertisement -
02 Kugel Komponents Dart block based Boss
The basis for Kugel’s bigger Boss is a Dart Machinery cast-iron block

To compete in the Trans-Am production class manufacturers had to go through the homologation process, which meant a certain number of “race” cars had to be available to the general public on showroom floors. The result of this process gave us some legendary cars, such as the Camaro Z28, Pontiac Firebird Trans-Am, American Motors Javelin SST Trans Am Edition, Plymouth AAR Cuda, T/A Challenger, and others, including the Boss 302 Mustang.

03 Price Motorsports Engineering (PME) supplied adapters to install the Cleveland heads on the Windsor block
Price Motorsports Engineering (PME) supplied adapters to install the Cleveland heads on the Windsor block, including this valley cover.

To be competitive in the Trans-Am production class Ford developed the Boss 302 V8 engine. Available in 1969 and 1970 Mustangs, these small block engines were based on high nickel block castings with four-bolt mains and screw-in soft plugs. But what really made the engine different from the standard 302 Windsor small block engines were the canted valve heads that were destined to be on the 351 Cleveland series of engines. These heads were vastly superior to the Windsor heads of the day; as the bore spacing and head bolt patterns were the same on the Windsor and Cleveland block, heads would interchange.

04 the block is modified by drilling and tapping two holes in each of the bulkheads
To attach the PME valley cover the block is modified by drilling and tapping two holes in each of the bulkheads.

Read More: Mom’s 1967 Pontiac GTO

- Advertisement -

The canted valve Cleveland heads offered a number of advantages compared to the standard Windsor inline valve arrangement. The Cleveland heads have big valves with generous ports that have straight paths in and out of the cylinders.  It should be noted that production Cleveland heads came in two configurations, 2V (2 venturi) and 4V (four venturi). The 351C-2V heads have smaller ports than the 4V that provide increased air velocity at lower engine speeds with open combustion chambers that result in a lower compression ratio for use with today’s pump gas. By comparison the 4V heads have huge ports that breathe extremely well at high rpm and closed, high-compression wedge chambers.

05 Windsor short block with special dome pistons
Here the modified Windsor block has the rotating assembly installed. Special piston domes with intake valve pockets are required when installing Cleveland heads.

As part of the Kugel Komponents family, Joe Kugel has taken part in the construction of a long list of outstanding hot rods for customers, and more than just a few were ’32 Ford roadsters. But in the back of Kugel’s mind was a vision of the car he wanted to build; the result of that vision is what he calls the “32MyWay” (see the Modern Rodding May ’23 issue for a full feature). While Kugel knew what he wanted his roadster to look like, as a member of Bonneville’s prestigious 200- and 300-mph clubs, performance figured into his plans as well. To that end he decided on an equally unique engine, a 427ci small block Boss V8 and an engine Ford never built.

06 The PME valley cover
The PME valley cover not only serves to close off the top of the block, but also keeps hot oil from splashing against the bottom of the intake manifold.

Handling the engine build was Mike LeFever of Redline Performance. The foundation of the bigger Boss is a Dart cast-iron block (PN 31385295) with a 4.125 bore and 9.200-inch deck height. It comes with four-bolt billet steel main caps; the three center caps have splayed outer bolts for maximum strength. The lubrication system has been upgraded with a low restriction priority main oiling system with external oil pump feed and the reinforced head bolt bosses are blind tapped to prevent leaks and produce accurate torque readings (extra-thick decks prevent head gasket leaks). Inside the Dart block is a Scat forged crank (PN 4-351C-4000-6200-2) with a 4-inch stroke. It connects to custom forged pistons with Scat H-beam rods (PN 6625021SA-1).

07 Windsor valves are in a straight line which requires the ports to make more restrictive sharper turns than the Cleveland design
This Edelbrock Ford head is typical of the Windsor design. Note the valves are in a straight line, which requires the ports to make more restrictive, sharper turns than the Cleveland design.

Read More: Timeless 1955 Ford Fairlane Victoria

- Advertisement -

To make this bigger Boss aluminum Edelbrock Performer RPM cylinder heads, PN 61625 was used. With the 2V port configurations the intake runner volume is 190 cc; combined with 2.05-inch intake valves and 1.60 exhaust valves these heads deliver great throttle response and power from 1,500 to 6,500 rpm. Combustion chamber volume is 60 cc and the heads came with pushrod guideplates.

08 The 60cc combustion chambers have a 2 02 inch intake and 1 60 exhaust valves
The combustion chamber side of the Edelbrock Windsor head. The 60cc combustion chambers have a 2.02-inch intake and 1.60 exhaust valves.

To adapt the Edelbrock Cleveland heads to the Winsor block Kugel turned to Price Motorsports Engineering (PME). Mary and Bill Price make a variety of adapters to install Cleveland-style heads on Windsor and other Ford blocks. In this case, due to the deck height of the block, their AP 16 kit (Cleveland 2V heads to a 351 Windsor block) was used to fill the gap between the Cleveland heads and the Windsor intake manifold. These adapters also provide passages to route the coolant so it exits the intake manifold.

09 Note the staggered arrangement of the valves in the Cleveland head
Note the staggered arrangement of the valves in the Cleveland head. The heads on the CLEVOR are Edelbrock while the camshaft, roller hydraulic lifters, and roller rockers are all from Comp Cams.

Although the Windsor rectangular ports and the Cleveland 2V head ports are the same height and width, they have slightly different corner contours. The adapters are made to match the intake and as Price explains, “This leaves very little of the Cleveland port showing when the plate is laid on for installation. This material can easily be removed or left alone.”

10 Cleveland head viewed from the combustion chamber side
Here is a Cleveland head viewed from the combustion chamber side. By staggering the valves, the ports are shorter and more direct and there is room for a slightly larger intake valve in the 60cc chamber.

Read More: How To Retain Your Classic Car’s Original Frame

Topping off the 427 is an eight-stack Borla throttle body electronic fuel injection system. We all know looks can be deceiving and this case what looks to be classic quartet of Weber carburetors are actually state-of-the-art, computer-controlled throttle bodies. The aluminum intake manifold has cast-in plenum facilities for the MAP sensor and idle air control while the throttle position sensor mounts to one of the throttle bodies. The fuel rail includes an adjustable fuel pressure regulator that’s good up to 1,400 BHP.

11 To use a 351 Windsor intake manifold with the Cleveland heads PME offers these spacers in their AP16 adapter kit
To use a 351 Windsor intake manifold with the Cleveland heads PME offers these spacers in their AP16 adapter kit.

The Boss 302 Mustangs had a short but colorful two-year Trans-Am career. Various issues plagued Bud Moore’s Ford team, arguably costing them the ‘69 Trans-Am season championship. The following year Moore won the Trans-Am champion with Parnelli Jones driving. Then in ‘71, Ford and all the other manufacturers dropped factory support for Trans-Am, as a result the glorious Boss 302 ended, but that doesn’t mean you can’t have one. While an original Boss 302 is nearly impossible to find, there are options available, like Kugel Komponents’s CLEVOR 427, the engine Ford didn’t build.  MR

12 The PME adapters are secured to the heads with counter sunk socket head screws
The PME adapters are secured to the heads with counter-sunk socket head screws.
13 With a 351 Windsor intake manifold installed
With a 351 Windsor intake manifold installed there is an air gap between it and the valley cover.
14 The intake manifold is an eight stack 351 Windsor style from Borla
The intake manifold is an eight-stack, 351 Windsor style from Borla. Note the thermostat housing up front.
15 Here the Borla throttle bodies are in place
Here the Borla throttle bodies are in place. The valve covers are Ansen, and the low-profile oil pan is from Aviaid.
16 the Ford engine is covered in a custom mix PPG Kugel Gray
Like the body, the Ford engine is covered in a custom mix PPG “Kugel Gray.”
17 Borla 8 stack system combines the classic look of carburetors with contemporary electronics
The Borla 8-stack system combines the classic look of carburetors with contemporary electronics. The air cleaners are from Borla, and the engine management system is from Holley.
18 Backing up the CLEVOR is a McLeod five speed manual transmission
Firing the plugs is an MSD distributor, the accessory drive and A/C compressor are from Vintage Air. Backing up the CLEVOR is a McLeod five-speed manual transmission.
19 ARP fasteners were used throughout the engine compartment and chassis
ARP fasteners were used throughout the engine compartment and chassis. Kugel built the 1-7/8 headers and 2-1/2-inch exhaust pipes dumped into mufflers from Stainless Specialties.

Sources

ARP
(800) 826-3045
arp-bolts.com

Borla Performance Industries
(877) 772-6752
borlainduction.com

Dart Machinery
(248) 362-1188
Dartheads.com

Edelbrock
(310) 781-2222
Edelbrock.com

Kugel Komponents
(562) 691-7006
Kugelkomponents.com

Mike LeFever/Redline Performance
(714) 777-5758
Redlineperformance.com

MSD
(866) 464-6553
Holley.com

Price Motorsports Engineering
(812) 546-4220
Pricemotorsport.com

Click on this issue’s cover to see the enhanced digital version of The Boss 427 Ford Never Made.mr february 2024

- Advertisement -

Related Articles

Search Our Site

More Modern Rodding

First Look 2024 Detroit Autorama Great 8

The 71st Annual Detroit Autorama & The Competition For...

A New Suspension on Jason Scudellari’s Brookville Model A

By Ron Ceridono   -   Photography By Jason Scudellari Over the...

Classic East Coast Styled 1934 Channeled Ford Coupe Personifies Kool

By Chuck Vranas   -   Photography by the Author With regard...

1955 Thunderbird With Shocking Looks & Performance

Coral Orange Ragtop Ford Thunderbird By Brian Brennan   -   Photography...

Dual Master Cylinder Conversion For Your Classic Car

Improving Braking Performance on a 1963 Impala With Classic...

LT4 Powered Tri-Five Chevy

Tri-Five Chevy With Modern Power Plant and Independent Rear...
More Modern Rodding

Hemi Swapped 1932 Ford Roadster

Dave Gray’s Deuce Roadster Built In only 5 Months By...

Under The 1965 Buick Riviera Detroit Speed Chassis

Unmatched Street Performance & Sixties Style By Gerry Burger   -  ...

Rodding Around

Goodguys 2023 Chevrolet Performance Builder of the Year Awards By...

Parting Shot

Gene Winfield Moves From His Longtime Home and Shop By...

MR’s Featured New Products For Your Hot Rod – 2024

Easy Passage This wire pass through kit (billet cover, custom...

Family Tradition

Building Your 1965 Chevelle With Big-Block Power Comes Easier...