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Why would I not have more hp & torque after a 305 TBI to 350 TPI swap

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Old 02-27-2016, 12:38 AM
  #101  
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Re: Why would I not have more hp & torque after a 305 TBI to 350 TPI swap

Originally Posted by Night rider327
I would take great heads all day long over 13 cid. On avg. most street type performance engines will only avg. out 1 to 1.5 HP per cubic inch.

So going from a 360 to a 383 is only 13 cid and will only gain you 13 to 20 HP.

A good set of heads will gain you 40-80 HP over your stock ones. Like say a set of vortec heads, you are looking at around a 35-45 HP gain. A set of Brodix IK heads around a 60 HP gain, a set of AFR heads around a 70-80 HP gain.

Heads are the #1 highest hp gain part (other than nitrous, turbo, supercharger) you can add.
Thanks I'm just waiting on estimates from the shop before I decide what to do. I think I'm looking for more low end torque though since its just a city cruiser. Is heads still the way to go? I no its not much but if the block is bored 60 over with a stoker kit it would be a 388 cid correct?
Old 03-05-2016, 09:57 PM
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Re: Why would I not have more hp & torque after a 305 TBI to 350 TPI swap

A 383 even with stock heads will make more bottom end torque than a 350 with good heads. I'm talking 3000rpm and below. If I were in your shoes I guess I'd go with the stroker and stock heads. You can always change the heads out later.
Old 03-10-2016, 02:28 AM
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Re: Why would I not have more hp & torque after a 305 TBI to 350 TPI swap

Originally Posted by 1MeanZ
A 383 even with stock heads will make more bottom end torque than a 350 with good heads. I'm talking 3000rpm and below. If I were in your shoes I guess I'd go with the stroker and stock heads. You can always change the heads out later.
I decided to go with the stroker. I had my transmission rebuilt and it ended up being less than what originally quoted so maybe I can get some heads to.
Old 03-23-2016, 02:42 AM
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Re: Why would I not have more hp & torque after a 305 TBI to 350 TPI swap

Anyone have any suggestions on a good cam. I was planning on using a comp cam just not sure which exact one I should go with.
Old 03-23-2016, 07:12 AM
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Re: Why would I not have more hp & torque after a 305 TBI to 350 TPI swap

268XFI HR13. make sure the heads have enough valve spring to run this much lift. my second choice would be the 260XFI HR13...
Old 03-23-2016, 11:29 AM
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Re: Why would I not have more hp & torque after a 305 TBI to 350 TPI swap

Originally Posted by 1MeanZ
268XFI HR13. make sure the heads have enough valve spring to run this much lift. my second choice would be the 260XFI HR13...
The 268 is the one the builder suggested but I had the wrong part number so comp cam told me it wouldnt fit my block and they suggested the 260 one I'm buying roller tip rockers and springs if needed so I'll probably go with the 268 but comp asked if I need a small base circle cam for the 383
Old 04-28-2016, 09:22 PM
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Re: Why would I not have more hp & torque after a 305 TBI to 350 TPI swap

I just bought an engine that was already built from a friend that wrecked his car. Its a 355 full roller high flow runners edelbrock heads. Now im not sure if my exhaust will fit with the extra quart oil pan or the oil cooler. I can probably modify the exhaust to fit the pan but do I really need the cooler?
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