EngineSpecs

Expanded Blueprint Specs:

The first thing you will notice is a whole lot more data than you get from the NHRA Tech Bulletins pages. That is why individual engines are shown rather than every available engine for the year-make.
The additional data that is not included on the NHRA Tech Bulletins pages is not authorized or approved by NHRA so do not assume that this has the same authority in those areas as the information on the official NHRA Technical Bulletins. The data from the NHRA web Technical Bulletins is included here and every effort is made to ensure that this data is the most up to date information published by NHRA.
An interesting tool is the link on the right side of the page to show all the cars that use the engine you have selected. You will find that information valuable in considering options for class placement for this engine.
You will find all the relavent information from NHRA for accepted replacement parts - pistons, rods, oil pans, etc. - is all located in this one page. You do not have to look anywhere else to find that information.

Engine Blueprint Specifications: 1961 Pontiac 235 HP 389 V8

PONT-61 Issued: 3/1/1961 Last Revised: 5/1/1970 Revisions: 3-15-62, 5-1-70

Engine Family: General Motors, Pont V8 Early Advertised Comp Ratio: 8.60:1 Induction: 1-4 Bbl Engine Type: V8

Basic Specs:	Bore	Stroke	Main Journal Dia	Rod Journal Dia	Max Bore	Max Stroke	Max Displacement
	4.063"	3.750"	3.000"	2.250"	4.143"	3.765"	406.0 ci

Piston-Rod Specs:	Piston Weight	Comp Height	Pin Weight	Rings	Rings Weight	Rod C/C	Max Rod C/C	Rod Weight	Min Assy Weight
	572 g	1.690"	90 g	5/64, 5/64, 3/16	55 g	6.625"	6.650"	760 g	1477 g

Compression:	Deck Height	Head Gasket	Piston Type	Dome/Dish Vol	Dome/Dish Hgt	Comb Chamber Vol	Max Compression
	.000"	.045"	Flat	0 cc	0	71.3 cc	11.24:1

Valve Train:	Int Rocker Ratio	Exh Rocker Ratio	Intake Valve	Exhaust Valve	Lifter Type	Spring Type	Lifter Dia.
	1.50:1	1.50:1	1.880"	1.600"	Hydraulic	Outer only	0.842"

Camshaft:	Intake Lift	Exhaust Lift
	.330"	.330"

Carburetors:	Number	Manufacturer	Trans	Type	Primary Throttle	Secondary Throttle	Primary Venturi	Secondary Venturi
	AFB-3123S	Carter	SM	4-Bbl	1.437"	1.686"	1.186"	1.563"

Notes:
	Class Limits	Available with Manual transmission only

Power Factors:	Stock Man		S/S Man		GT Man		GTFwd Man
Base Factors	240		250		250		250

Accepted Replacement Pistons for Stock Eliminator

   Effective 1/9/2023
Specs:     Comp Hgt-1.690"    Pin Dia-0.980"    Rings-5/64, 5/64, 3/16
Distance to Top Ring-0.280"    Piston Min Weight-572g

Manufacturer	Part Number

Federal-Mogul

228P

278567

Ross

138822

Venolia

335-360

Venolia

389-318

Accepted Replacement Oil Pans for Stock Eliminator

Engine Group - Pont V8 Early Effective 5/10/2022

Manufacturer	Part Number

Milodon

30770

Moroso

20492

Accepted Replacement Blocks

Manufacturer	Part Number

K&M Performance

MR-1

All Pontiac

APSJB

Accepted Replacement Connecting Rods for Stock or S/S

Effective 8/23/2023
Specs: C/C Length- 6.625" Min Weight- 760g Journal Dia- 2.249" Big End Dia- 2.375" Pin Dia- 0.980"

Manufacturer	Part Number	C/C Length	Wgt.	Pin Dia.

Carrillo

C427-76635S

6.625"

834g

0.990"

Pontiac

Carrillo

C427-A76635H

6.625"

787g

0.990"

Pontiac **Discontinued**

Carrillo

P-455-SS

6.631"

760g

SUPER STOCK ONLY

Childs & Albert

389-12

6.625"

0.947"

Pontiac

Crower

F91059

6.625"

0.981"

Pontiac

Crower

ML93015B5

6.624"

773g

SUPER STOCK ONLY

Crower

SP93419

6.625"

830g

0.947"

Pontiac

Eagle

CRS-6625P3D

6.625"

760g

0.947"

Pontiac

Eagle

CRS-6635P

6.635"

810g

0.990"

BB Chev

Manley

14168

6.635"

830g

0.990"

BB Chev

Oliver

ORPPONT6625

6.625"

0.981"

Pontiac

Oliver

P6225PONT

6.625"

790g

0.980"

Pontiac

Oliver

P6625PONTFR8

6.625"

819g

0.980"

Pontiac

Note the calculations for actual displacement the maximum actual compression ratio.

Would you like to see a list of all the cars where this engine is used? Click here: