Swapping 400 sb for 350 sb
12-23-2001, 03:54 PM
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Swapping 400 sb for 350 sb
Well... i just made the last payment on my car and am ready to get serious... Has anyone put a 400 in 3rd gen... if so what are your likes and dislikes about it?? Is better or worse than 350....
12-24-2001, 03:24 AM
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Car: 82 & 91 Firebird
Engine: 400 & 355
Transmission: TH350 & 700
Axle/Gears: 4:11 & 2.72
I did my 350 to 400 swap last year. I love the 400. The only thing I would change is I used stock 400 rods, I should have used 350 rods or 6in. That mistake will be fixed next time around. The best I ran with my 350 was 8.66 in the 8th, 2 race seasons tweaking. The first pass with the 408 was an 8.61. And my best pass this year was 8.21. After the .21 pass the tranny started slipping and the times only got worse. Id say if you have the time and the funds build one, If not get NOS,and use the 350.
Later
John
Later
John
12-24-2001, 02:29 PM
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how much money we talking about???? i gotta get me another tranny anyway... same with the rearend... I'm gonna need it after I get the HP figures I'm looking for
12-25-2001, 07:17 AM
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Car: 82 & 91 Firebird
Engine: 400 & 355
Transmission: TH350 & 700
Axle/Gears: 4:11 & 2.72
I don't have the exact figures, But off the top of my head.
Block,rods w pistons installed, and macine work done= $400
Re-ring Kit from Northern=$100 ?? Its close
heads (new Iron eagles)=$1000
STreet Dominator Intake=$120
Speed Demon Carb =$480
Misc, Head bolts,mains...=$150
Short block balancing =$150
Est Total =$2400
Thats not to bad, but I got a deal on the block, and pistons. I probably saved 200-300 there. I looked at it this way I could have saved a lot of money, By using stock heads, Intake. But a stock short rod 400. Is marginally faster then a stock 350, and in alot of cases the 350 will be faster. I still say of your going to do it go all out, DON"T half a-- it.
You said you needed a new tranny and rear, I can't remember if you have an auto or stick. If you have an auto your rear will most likely live just fine for a while. I haven't had any problems with mine behind eithor the 350 or the 400, I am running BfG 275 50 drag radials. Steven(moderators) 7.5 lived behind a BBC for a year, He did change it this winter though. I would suggest the rear be the least of your worrys.
Merry Christmas
Later
John
Block,rods w pistons installed, and macine work done= $400
Re-ring Kit from Northern=$100 ?? Its close
heads (new Iron eagles)=$1000
STreet Dominator Intake=$120
Speed Demon Carb =$480
Misc, Head bolts,mains...=$150
Short block balancing =$150
Est Total =$2400
Thats not to bad, but I got a deal on the block, and pistons. I probably saved 200-300 there. I looked at it this way I could have saved a lot of money, By using stock heads, Intake. But a stock short rod 400. Is marginally faster then a stock 350, and in alot of cases the 350 will be faster. I still say of your going to do it go all out, DON"T half a-- it.
You said you needed a new tranny and rear, I can't remember if you have an auto or stick. If you have an auto your rear will most likely live just fine for a while. I haven't had any problems with mine behind eithor the 350 or the 400, I am running BfG 275 50 drag radials. Steven(moderators) 7.5 lived behind a BBC for a year, He did change it this winter though. I would suggest the rear be the least of your worrys.
Merry Christmas
Later
John
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