[LIPE02]

I'm starting a ground up restoration of a !971 Lermans Sport Convertible. Want it hot but not a "race car." I have a 400cid code #H092, also has a large "73" right by the distributor hole, arrow points to "D." I also have a 350cid code #E122, arrow points to "N." So, I was trying to decide which motor to use when up pops a 389! I don't have the codes on it but I sure like the idea of the 389. Am I setting myself up for trouble using it, i.e. wiring etc. Please give me some feedback. Thanks guys!

[Scarebird]

Nothing wrong with the 400 - what is that letter code on the center exhaust ports of the heads?

another 71 sport rag owner...

[Half-Inch Stud]

wires & hoses all the same.

Your question is all about the short-block. OUR answer will be based in your intended application. Being a Convertible doesn't decide 350/400. But the rear gear may.
If a 2-series (2.73:1, 2.54:1) then 400 engine. If 3-series (3.08:1, 3.23:1) then 400.

[Dick Boneske]

Why would you want a 389 vs. the 400 you already have? The 400 is a 389 .060" overbored and will fit the motor mounts for the '71 LeMans. The 389 will need special mounts to adapt it to the '71 chassis.

Also, if it's a pre-1964 389, the starter mounting boss is not on the engine. The starter on these earlier engines was mounted on the bell housing.

I can't think of a single reason, other than originality in an earlier chassis, to prefer a 389 over a 400, 428, or 455. All four weigh roughly the same, have the same outside dimensions, and cost the same to rebuild. But, the larger the engine, the more power it makes. There's no penalty for the larger engines with a Pontiac.

[The Boss]

Originally Posted by Half-Inch Stud

Being a Convertible doesn't decide 350/400. But the rear gear may.
If a 2-series (2.73:1, 2.54:1) then 400 engine. If 3-series (3.08:1, 3.23:1) then 400.

Instant classic!

[Scarebird]

by HIS's logic D = Da, N = nyet

[Half-Inch Stud]

Coooool!: http://www.youtube.com/watch?v=040y9...eature=related


something for EVERYBODY there.

[pont3]

Depends on how you will use the car. I prefer the 400 over ALL other Pontiac engines for ocassional driving and cruising. The 455 for torque and all out performance, and another source for daily driving.

[Mister Pontiac]

Originally Posted by Half-Inch Stud

wires & hoses all the same.

Your question is all about the short-block. OUR answer will be based in your intended application. Being a Convertible doesn't decide 350/400. But the rear gear may.
If a 2-series (2.73:1, 2.54:1) then 400 engine. If 3-series (3.08:1, 3.23:1) then 400.

I agree with the Boss about Half-Inch Stud... Instant Classic! LOL!

Seriously though, I would say the 400 as well. Use the biggest/best of what you have IMO.

[BB1968]

This is JMHO but "there is no replacement for cubic in displacement"....especially when it doesn't cost anymore to get the job done...

[rad400]

400 with a stroker kit.

[chiphead]

Either 400 or 400 block with stroker kit.

The 389 and 350 have the same stroke as the 400 (3.75") but much smaller pistons. The 389 is the predecessor of the 400. The pistons on the 389 are .060" smaller and the heads are more restrictive than the 400 heads. But the 389 is no slouch, it was just replaced by the 400 in '67.

The 350 is a smaller engine that came out in '69 to replace the 326. It has smaller pistons than the 389, and it suffers from valve shrouding because the bore is so small. It will still run, and capable of 325 HP when hopped up. You can't bore it out to a 389 or 400.

Most people build 400s, because the cost is the same as a 350 and you can get another 100 HP out of them at the same level of tune. But the current trend is to stroke the 400 block to 460-488 cubic inches using stroker crank kits. 450-550 HP is the norm for those engines on pump gas and with good street manners!

[Half-Inch Stud]

YET none of the ladies will give a hoot about what engine is in the convertible:

Originally Posted by Half-Inch Stud;[url

http://www.youtube.com/watch?v=040y9XC1OC0&feature=related[/url]

something for EVERYBODY there.

[GoatDr]

By the way, the N stands for night and the D day. It just denotes the work shift it was cast on.

[Half-Inch Stud]

Originally Posted by GoatDr

By the way, the N stands for night and the D day. It just denotes the work shift it was cast on.

Still waiting to pummel the clown that insists it's "Nodular vs Ductile".

[PunchT37]

Run the 400 with a set of the cast iron 72cc heads [670,16,48,62,12,13 etc.] or KRE D`s if you`re not too picky on a restoration that doesn`t have factory heads.

['ol Pinion head]

Originally Posted by Half-Inch Stud

wires & hoses all the same.

Your question is all about the short-block. OUR answer will be based in your intended application. Being a Convertible doesn't decide 350/400. But the rear gear may.
If a 2-series (2.73:1, 2.54:1) then 400 engine. If 3-series (3.08:1, 3.23:1) then 400.

8.2 Pontiac 10 bolt rears never came with 2.73's or 2.54's. Which rear & what ratio of gear one ends up running will depend on a myriad of things, no reason to saddle one's engine build choices to what Pontiac threw in a gray iron 8.2 ten bolt housing in your '71 convert. As a '71 LeMans Sport convert, if it was mine, I'd take the H092 dated 400 block have it ck'ed for worthiness, if no freeze cracks or major overbore, build this 73 400 up with a stroker crank, good forged rods & anything from a set of street-ported '71 96 casting d-ports to a set of 87cc alum heads. A build tailored for 500-550 ft/lbs of torque at around 3000 rpm, then have a 8.5 A-body built with a new Eaton & 3.08's. Should have a gob of torque & will not need a lot of gear, like if it was built as 406 with big valve high compression D-ports.