Forged Stroker Pistons

 

CID

Bore

Stroke

Flat/dished

Rod length

Ring part #

Piston Part#

Piston Price

 

434-440

4.155-4.185

4.0"

Flat 4.3cc

6.800 BBC

2M5529

KB937

$499.00

 

461-468

4.155-4.185

4.250"

Dish 10.6

6.800 BBC

2M5529

KB938

$499.00

 

461-468

4.155-4.185

4.250"

Flat 4.3cc

6.800 BBC

2M5529

KB941

$499.00

 

488-501

4.155-4.210

4.500"

Flat 4.3cc

6.700 BBC

2M5529

KB942

$499.00

 

488-501

4.155-4.210

4.500"

Dish 16.8

6.700 BBC

2M5529

KB943

$499.00

 

461-474

4.155-4.210

4.250"

Dish 30cc

6.635 BBC

2M5529

KB981

$499.00

 

505-538 *

4.350 – 4.360

4.250 or 4.500

Flat 17.3 cc

6.700 or 6.800

2M5528

KB631

$559.00

 

 

 

 

Spotts Performance offers FORGED stroker pistons for both the cast and forged aftermarket crankshafts for Pontiacs. All pistons are sold as a set of 8. You can now increase both 400 and 455 blocks from 434 to 501 CID’s! Aftermarket blocks from 505 to 538 without custom pistons

The KB981 was developed by Spotts Performance for use in “stealth” engines so pump gas can be used with 72 cc’ iron heads. We have built many stock appearing 4bbl. Tripower and even RAIV’s as pump gas 461 plus engines. Stock looking engines, street, strip or race engines can now be increased from 461 to 501 CID without ordering expensive custom made units. Pistons are quality forged units with .990 BBC style pins included and pin fitted. Pistons allow use with factory heads, Edelbrock, KRE and others. Note – certain larger intake valves on ported aftermarket heads may not work (except for KRE high ports!). We also offer complete rotating assemblies, complete short blocks, or complete crate engines! 

 * NOW AVAILABLE – large bore aftermarket block pistons for KRE MR1 and IAII aftermarket blocks! Another piston designed by Spotts and KB to allow both 4.250 and 4.500 stroke cranks to used in the aftermarket blocks. The compression height is 1.292 and with 4.250 stroke and 6.800 inch rods, the stack height is 10.217. The piston will be in the hole and block will be needed to be decked for proper compression ratio with heads used. When the KB631 piston is used with a 4.500” stroke and the 6.700 long rod, the stack height is 10.242 – so on a 10.240 deck height block, the piston will be out of the hole .002    

Engine

Bore

Compr.

Flat/dished

Type

Rings

Part#

Price

389

60

9.8

Flat 4 v r

FHR

2M644

KB9946 std

$399.00

400

STD 30-40-60

9.8

Flat 4 v r

FHR

2M644

KB9946

$399.00

400

30 40 60

9.5

Dish 14cc

Forged

2M5529

KB891

$449.00

400

30 40 60

10.5

Flat 6cc

Forged

2M5529

KB890

$426.00

428

30-40-60

10.5 w/72

Dish 10cc

Forged

2M5529

KB892

$449.00

455

30 40 60

9.3 w/100cc

Flat 6cc

Forged

2M5529

KB888

$426.00

455

30 40 60

10.6 w/72

Dish 15cc

Forged

2M5529

KB889

$449.00

Notes. FHR is forged head relief – all other pistons completely Forged. All pistons accept full float or press fit rods. All above pistons are for stock spec rods - length, big end, pin bore and stock strokes. Stroker pistons listed separately. Will not accept factory ring packs (except FHR)– must order rings listed. All pistons accept stock or Edelbrock heads.

KB Pistons

Engine

Bore

Compr.

Flat/dished

Type

Rings

Part#

Price

389

30-40-60

10.5

Flat 3.5cc

Hypereutectic

2M639

KB370

$319.00

389

.060 4.120 bore

9.5

Dish 17cc

Hypereutectic

2M644

KB346-std

$339.00

400

Std 30 40 60

9.5

Dish 17cc

Hypereutectic

2M644

KB346

$339.00

400

30 40 60

10.5

Flat 6cc

Hypereutectic

2M644

KB133

$319.00

421

60-4.150

11.3

Flat 6cc

Hypereutectic

2M644

KB304-30

$319.00

428

30 40 60

11.3

Flat 6cc

Hypereutectic

2M644

KB304

$319.00

455

30 40 60

9.5 w/72cc heads

Dish 30 cc’s

Hypereutectic

2M643

KB371

$339.00

455

30 40 60

9.5 w/96cc heads

Flat 6 cc

Hypereutectic

2M643

KB222

$319.00

455

30 40 60

9.0 w/105cc heads

Dome 0 cc

Hypereutectic

2M643

KB347

$319.00

Notes: hypereutectic pistons require the upper rings to be gapped wider – pistons will work with press fit or bushed rods – pistons include pins and locks. All above pistons are for stock spec rods - length, big end, pin bore and stock strokes. The dished 389 pistons are 400 pistons and only available in 1 size (4.120 bore)


 

Ross Pistons
Part #FP1 Ross pistons flat tops $639.00
Part #FP2 Ross pistons dish or dome top $659.00
Custom Ross pistons available in most bore sizes, ring grove sizes and pin heights. Flat dome or dished in many configurations. Custom dish or dome available for additional fee. Pins are extra cost - we carry both Ross and Ferrea pins listed below.

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Piston Pins - full float
Part# Size Weight Price ea.
P70014 .990 X 3.000 133 G $15.00
P70028 .990 X 2.930 138 g $15.00 (most popular - used with Ross pistons)
P70060 .990 X 2.500 123 g $15.00
P980 Ross .980 X 2.930 146 g $86.00 (used with Ross pistons and stock Pontiac rod sizes)
Other sizes available.
Call or EMAIL for prices.

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