i think i have a 350 in my 1971 lemans sport, how do I know for sure? Also, what would be the right size 4bbl to put on to replace the2bbl?

45

Asked by May 25, 2014 at 08:43 AM about the 1971 Pontiac Le Mans

Question type: General

8 Answers

107,615

Check the block casting number. These are found on the driver's side of the engine, at the back of the head on the transmission mounting flange. You can use a mirror to see it.

2 out of 2 people think this is helpful.
107,615

http://outintheshop.com/faq/casting/castings2.html -- check casting number against this list.

2 out of 2 people think this is helpful.
3,125

there is also the engine it code on the front of the block just below the head on the passenger side . engine size should also be stamped on the side of the block near the motor mounts .

1 out of 1 people think this is helpful.
3,125

To address your 4 barrel question , if the engine is stock , leave it the way it is , you'll just spend more money in gas then anything else ! To put a 4 bbl you have to change the intake manifold . the carb doesn't need to be any bigger that a quadra jet , make sure it's made for that engine & not a chevy .

1 out of 1 people think this is helpful.
45

A prior owner already made the switch, I think the carb is bad and wasn't sure what is a correct size to replace with.

4,525

The 350 with automatic will run fine around 600-650 cfm with no other modifications. With 4 speed, cam, headers, and dual plane intake you can push 650-700.

45

Thank you!

3,125

A rochchesrter which is probably what you have now is the best carb for that engine , you can pick one up at a swap meet or on ebay make sure it a match for that engine . good luck

Your Answer

Add photo
Le Mans

Looking for a Used Le Mans in your area?

CarGurus has 19 nationwide Le Mans listings and the tools to find you a great deal.

ZIP:

Search Pontiac Le Mans Questions

Pontiac Le Mans Experts

#1 Rucko
Rucko
Reputation 440
#2 Js08016
Js08016
Reputation 180
#3 Daniel Perron
Daniel Perron
Reputation 160
View All

Related Models For Sale

Used Pontiac GTO
431 listings starting at $5,995
Used Pontiac Firebird
7 Great Deals out of 789 listings starting at $1,800
Used Chevrolet Camaro
132 Great Deals out of 35,283 listings starting at $1,995
Used Chevrolet Impala
566 Great Deals out of 28,668 listings starting at $1,595
Used Pontiac Grand Prix
21 Great Deals out of 2,855 listings starting at $1,595
Used Chevrolet Nova
160 listings
Used Buick Skylark
101 listings
Used Dodge Charger
246 Great Deals out of 27,238 listings starting at $1,997