Engine Mounts, Plates, & Cradles
Pontiac V8 Engine Mounts, Plates, & Cradles
Hold It Where It Belongs — Engine Mounts, Plates, & Cradles for Pontiac V8s
Engine Mounts, Plates, and Cradles are what hold a Pontiac V8 in place and keep it from twisting a header into a frame rail. A Pontiac mount is really two pieces — the frame mount bolted to the chassis and the engine mount bolted to the block — and Pontiac changed the block bolt pattern part way through, so the year of your engine and the year of your car both matter.
Butler stocks Mity Mount reinforced rubber, polyurethane and stainless, CNC billet poly and solid engine mounts, Butler adapter kits for mismatched engine and chassis years, front and mid motor plates, transmission adapters and engine cradles.
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More About Engine Mounts, Plates, & Cradles
1. Two Halves, Two Part Numbers
A Pontiac mount is a pair of parts. The frame mount bolts to the chassis, the engine mount bolts to the block, and a through bolt clamps them together. Butler sells them separately and in matched kits, because plenty of cars need one and not the other.
| Frame mounts | Reproduction frame mount sets for 1964-72 A-body, 1967-69 Firebird in a four piece set, 1970-74 Firebird in a two piece set, and 1975-81 F-body in rubber, poly, CNC billet poly and solid. |
| Frame mount spacers | The 1964-72 A-body spacer fixes the oil pan rubbing the crossmember, which shows up most with aftermarket pans. Butler also recommends it with IAII blocks, where the oil pan rail sits 1/8 in. lower in an A-body. A 3/16 in. spacer is stocked for 1975-81 F-body. |
| Two-bolt versus three-bolt blocks | Pontiac blocks through 1969 use a two bolt engine mount pattern; later blocks use three. That fact drives most of the adapter kits below. |
2. Rubber, Poly, Billet or Solid
This is the real decision on the page, and it trades isolation against control. More horsepower and more mount stiffness go together; so do more stiffness and more noise through the floor.
| Mity Mount steel reinforced rubber | Modified stock-type rubber mounts with the driver side torque mount reinforced to limit stretch under acceleration, warranted for engines up to 125 percent of their factory horsepower rating. |
| Polyurethane and stainless | Interlocking poly and stainless mounts, with the 1967-69 Firebird and X-body set rated good for 650-plus horsepower. They also fit the Detroit Speed bracket for F-body cars with a hydroformed subframe. |
| CNC billet poly frame mounts | For 1975-81 F-body, milled from 6061 billet aluminum with molded poly inserts and billet sleeves, rated to 650-plus horsepower, and they do not change original engine height. |
| Solid mounts | No isolation, maximum control, the honest choice for a drag car. Stocked for 1964-72 A-body, 1967-69 Firebird and 1972-74 X-body, 1970-74 Firebird, 1975-81 F-body and 1959-64 full size. |
| The poly heat warning | If you are running headers or Ram Air manifolds with polyurethane mounts, ceramic coating is strongly recommended, along with a heat shield or header wrap. Excessive heat will melt or deteriorate the poly. |
| The solid mount block warning | IA2 blocks must be clearanced and notched higher to fit the solid mounts. |
3. Fitment by Car, and the 455 Exception
| 1964-72 GTO, LeMans and Tempest | Mity Mount rubber, poly and stainless, and solid mounts. Note the exception: 1970-72 GTOs originally equipped with a 455 used a different three hole mount, and to run the poly or solid mounts on those cars you have to change to the AAU-N245A frame mounts. |
| 1967-69 Firebird and 1972-74 X-body | These share mounts with Catalina and Bonneville of the same era. Mity Mount rubber, interlocking poly and stainless, and solid. |
| 1970-74 Firebird and Trans Am | The three hole mount, shared with 1970-73 GTO and LeMans cars built with a factory 455 and 1970-73 Grand Prix. Rubber and solid. |
| 1975-81 Firebird and Trans Am | The largest group here, with rubber, poly, billet poly and solid frame mounts, spacers, and the Butler F10774 adapter kitted with each frame mount type. |
| Full size and big car | Solid mounts for 1959-64 full size cars and 1968-69 Grand Prix with the 428. |
4. Adapter Kits: Different Engine Year, Different Chassis
Swapping a later engine into an earlier car, or an earlier engine into a later car, is routine on a Pontiac. Butler builds the plates that make it bolt up.
| MM6 | Puts a 1969-and-earlier engine, with only two mount holes, into a 1970-and-up chassis. Two adapter plates plus grade 5 bolts, lock washers and flat head bolts. Use the original chassis specific frame and motor mounts. |
| MM5 | The reverse — a 1976-and-up engine into a 1969-and-earlier chassis, or a 1970 LeMans. |
| F10774 | Puts a 1961-1979 326-455 into a 1975-81 F-body, and its extra bolt holes will adapt a 1961-69 two bolt block for use in a 1970-81 F-body. Offered as a bare adapter with hardware, or kitted with rubber, poly, billet poly or solid frame mounts. Excludes the 403. |
| Warpath adapter kits | 1965-69 two bolt block into a 1975-81 F-body, with or without a rubber frame mount. Some 389 and 428 blocks may have to be clearanced, and the version with the frame mount may interfere with some headers. |
| Expect to fit, not just bolt | Adapters may require some modification or slight shifting of the frame mounts for proper alignment, both because of the adapter thickness and because of tweaks in a fifty year old frame. |
| Starter adapter for 1961-64 blocks | Mounts a starter on an early block behind a later transmission. It requires the early bellhousing style starter and a 1965-or-later flexplate, and on a 1963-and-earlier block the transmission bolt holes go from 3/8 in. to 7/16 in. The pre-64 crank pilot measures 1.625 in. against a converter snout around 1.75 in., so it must be opened and deepened. Automatic only. |
5. Motor Plates, Mid Plates and Transmission Adapters
| Front motor plates | All Pontiac front plates bolt on through the four lower timing cover bolts behind the balancer, free up a lot of room and give you somewhere to hang an alternator. Stocked universal and in 1964-67 A-body, 1968-72 A-body and 1970-81 F-body, with angles and bolts, plus a version with spacers for a Meziere water pump. |
| The front plate gotcha | Manual fuel pumps may not work with front plates. Plan on an electric pump if you are going this route. |
| Mid plates | A 3/16 in. thick steel mid plate with a dual bolt pattern, 32 in. wide, including torque converter spacers, and a 3/16 in. by 32 in. aluminum version. |
| Transmission adapters | A 1/8 in. plate to adapt a Pontiac engine to a GM transmission including TH350, TH400, 700R4 and 200-4R, which also works with Buick, Olds and 403, plus the TCI Chevy-to-BOP plate. The TCI midplate and SFI shield needs the top four bellhousing bolts drilled and the starter gear hole cut. |
| Crossmembers | American Powertrain X-Factor adjustable aluminum crossmembers in 20-26 in., 26-32 in. and 30-34 in. between the rails, bolt in or weld in. |
| Driveshaft loops | No drill, no weld bolt-on loops for TH400 and for TH350, 200R4, four speed, TKO and TKX, Powerglide, 700R4 and 4LE, built to NHRA spec at 2 in. wide and .250 in. material. On a TKO you may need to remove the torque tube bolt bosses to clear the loop. |
6. Cradles, Lift Plates and Storage
| Butler engine cradle | The Butler exclusive 1961-79 Pontiac V8 storage and transport cradle, laser cut and powder coated, with hardware to the block. It is the exact cradle that ships with all Butler Performance engines, with or without wheels, and the base plate holes take casters or bolt to a pallet. |
| Heavy duty cradle | An All Star 1961-79 Pontiac V8 cradle in black powder coat, with heavy duty casters available as an add-on. |
| Lift plates and hoist brackets | A carburetor flange lift plate for Holley 4150, 4160 and 4500 Dominator, Rochester Q-jet, Carter, Motorcraft and Edelbrock patterns, and a hoist bracket that mounts in the factory front location. |
| Storage port covers | D-port and round port cover sets for 326-455 engines, covering intake ports, exhaust ports, the fuel pump opening and the distributor hole. Hardware not included. |
| Oil pan protection | A 3/16 in. steel skid plate for 1964-72 GM A-body cars, designed after a Butler-equipped GTO nearly lost a road race pan. |
If you are mixing an engine year and a chassis year, tell us both, plus the block casting and whether you run headers or manifolds. That is usually enough to get the mount, the frame mount and the adapter right the first time.
Engine Plates & Adaptors Motor Mounts
Not sure what your Pontiac needs?
Email our tech team at tech@butlerperformance.com. Tell us your engine, heads, car, and power goal, and we will put the parts together as one combination that works.