[flyrpwc2002]

i have two engines for my 68 firebird. i have the original 350 and a 74 catalina 400. over the winter months i would like to build a motor and was wondering if it would be possible to build a stroker motor with these two motors?
also what parts would be best to put on it?
i am looking for a strong motor that can be driven on the weekends and not having to brake the bank for gas.

[flyrpwc2002]

i have two engines for my 68 firebird. i have the original 350 and a 74 catalina 400. over the winter months i would like to build a motor and was wondering if it would be possible to build a stroker motor with these two motors?
also what parts would be best to put on it?
i am looking for a strong motor that can be driven on the weekends and not having to brake the bank for gas.

[AIR RAM]

I have built my 350 to run 13.5 @108, but if I where to do it again and Had a choice I would have built a 400. At the time I was in Italy and the 350 was all I had so I built it throwing on:

*E heads
*.040 cast TRW pistons
*Fluidamper Balancer
*4 bolt mains
*Eagle rods (PRESS)
*Comp Cams Grind # P268-4/268-4 H110
@. 050 In+Ex 222, Gross Lift In+Ex .463 at 110 Separation.
*RPM intake
*EDL 750CFM W/2" spacer
*THM400 with an Eaton 4.10 10 bolt.

I knew one day I would have a 455 so I just spent it on the 350 for the time being.

The problem is the 350 cylinders are too small and cause shrouding of the valve. I had to hand grind small reliefs for the intake (2.11) and exhaust (1.66) valves to clear in the cylinder walls paying close attention not to hit "ring land.” Also With such large valves and small bore created bad low-end AIR velocity entering the cylinder. It did not make its power till 2800-3000 RPM but held it all the way through 5800. With a 400 you would not have this problem. Go with the larger 400, make more HP for less.

SPEED SAFE, AIR RAM

Im putting together a .040 455 with Edelbrock heads (72cc), Eagle Rods, Dished J&E Pistons for 10.5:1, Harlem sharp roller Rockers, Fluidampner, Edelbrock Performer RPM intake, and 750 Demon Carb. Looking for Low 12s in the 1/4.......LOL

[drewhelm1974]

In addition you wouldn't be able to use the 400 crank as a "stroker" crank like a SB Chevy as the Pontiac 400 and 350 crank is the same.....

69 Firebird, FINALLY installed the Pontiac 469.
01 Red and pewter GMC Ext Cab SIERRA SLT 4x4
02 Maple Red (maroon) LS1 Trans Am

[Skip Fix]

326-400s all use a 3.75 crank.

[MoJo]

Cast pistons for a P350 are more expensive than 400 pistons. Expect to pay $200+ retail for simple cast 350 slugs. Supply and demand-

[flyrpwc2002]

does anyone know which motor would be cheaper to build the 350 or the 400?

for a twelve second et

the guy i bought the car from put an edelbrock rpm intake amd a 600 cfm carb on the 400 and he says their is also a cam in it. but he gave me wierd numbers for the cam s i am not sure about that.

[flyrpwc2002]

he also said that he ported the 4x heads.

[WARPed]

With all things being equal the 400 will cost less to build and will yield more power so with out question the 400 is the way to go.

with out questions there can be no answers

1969 Grand Prix
[email protected](1.358)
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WARPed Tepee Forums
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[Will]

Time to do some research.

The 400 will be a cheaper motor to build and will produce far better results for the money spent.

But, I get nervous when I hear about people who port heads put on an RPM intake and possibly a big cam then top it off with a 600 cfm carb (too small!).

Are the 4X heads the original heads for this engine? If so, the compression ratio is about 8:1, maybe slightly higher depending on if the block has been bored and decked or the heads have been milled. If they came off a 455, the compression ratio is in the toilet, like maybe 7:1 if you're lucky.

You can identify which 4X heads you have by looking for a stamped code. This code is located on a flat milled on the accessory boss near the left end of the head as viewed from the exhaust side. In other words if you're looking at the head like you would be if putting spark plugs in it, you will see a boss between the two left most spark plug holes near the top of the head. The top of this boss is machined flat and there is a code stamped on this flat. Find that code then go to www.wallaceracing.com and look at their head codes page.

You might actually be better off to take the heads off the 350, modify them for 2.11/1.77" valves and screw in studs, have a light porting job done on them by someone known to be competent, and put them on the 400. Compression ratio will be in the mid 9:1 range then.

The RPM is a good intake, definitely worth having on a 400.

Have you heard the engine run? Does it have any lope to the idle like a big cam would cause? What does he have to say about the cam?

[FAPhoenix]

Does anyone know of a Core 400 (67-69) in Alberta Canada (I think I asked this before somewhere).

Tyler

[flyrpwc2002]

I talked to the guy who sold me the car. he told me that he put a very mild cam in it he said he couldnt quite remember but like a 277/311 or something i didnt know quite what he meant lift/duration wise.

[Rick Lightfoot]

Sell the 350's to a engine builder in Ca. who gets 700 hp out of them. [img]/infopop/emoticons/icon_rolleyes.gif[/img] Stick with a 400 minimally.

[Half-Inch Stud]

Excellent advice above.

[FAPhoenix]

Got the e-mail address ofthis 700hp man? Since I'm looking for a 400 dropping the 350 would be nice.

Tyler

[FAPhoenix]

Got the e-mail address ofthis 700hp man? Since I'm looking for a 400 dropping the 350 would be nice.

Tyler

[67droptop455]

Tyler, check with Craig the "coreman" [email protected] in in the Vancouver B.C. Area.
He has a 68 Firebird convertible, and runs an engine core business... ships all over Canada
and the US.

If anyone in the great White North would have what you need he will!

Brett - 67 Drop Top 455!

[FAPhoenix]

Thanks [img]/infopop/emoticons/icon_smile.gif[/img]

Tyler