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Im converting my 1988 320 hp efi small blocks to carb. Recommend?

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Im converting my 1988 320 hp efi small blocks to carb. Recommend?

Old 12-30-2020, 10:36 AM
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Default Im converting my 1988 320 hp efi small blocks to carb. Recommend?

At 5400 rpm its oriinal rating was 320 hp. Im removing the efi intake and installing dual plane intakes and new carbs. What has anyone done with this combo? 750 cfm marine edelbrock? 600 cfm marine quik fuel? Intake?
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Old 12-30-2020, 09:01 PM
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Air gaps and 750 quick fuels would be my first option on a 300 hp small block but I have no before and after data to share.
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Old 12-30-2020, 10:40 PM
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My opinion with under 350hp, 600-650 Holley based. I prefer with dual inlet and with dual metering blocks.
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Old 12-31-2020, 04:46 AM
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ok thx
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Old 12-31-2020, 04:50 AM
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Originally Posted by SB View Post
My opinion with under 350hp, 600-650 Holley based. I prefer with dual inlet and with dual metering blocks.
ok thx. do you think a 750 edelbrock square with vac secondaries would be too much? Also there is a 670, prob a better choice?Aluminum Marine Avenger 4150 4-BBL Carburetor 670 CFM
SKU # 510-0-82670 Jeggs?
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Old 12-31-2020, 08:29 AM
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Originally Posted by oconnormarine{
Aluminum Marine Avenger 4150 4-BBL Carburetor 670 CFM
SKU # 510-0-82670 Jeggs?
https://www.jegs.com/i/Holley/510/0-82670/10002/-1
]


Itís got everything that would check all my boxes. Even quick change vac secondary spring cover, that I add most times when installing vac secondary carb.

Last edited by SB; 12-31-2020 at 08:32 AM.
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Old 12-31-2020, 08:55 AM
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Originally Posted by SB View Post
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Itís got everything that would check all my boxes. Even quick change vac secondary spring cover, that I add most times when installing vac secondary carb.
ok thanks man!
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Old 01-03-2021, 01:58 PM
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Originally Posted by ph1971 View Post
Air gaps and 750 quick fuels would be my first option on a 300 hp small block but I have no before and after data to share.
I agree with this. I had mechanical secondary edelbrocks, quadrajets, and finally a 750 mechanical secondary carb on my 350. the mechanical 750 is the way to go. The other carbs felt laggy and unresponsive comparatively.
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Old 01-03-2021, 06:42 PM
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On my 350 vortec the 750 edelbrock was a mph faster than the 600. I would put a double pump quickfuel 650 on it they are nice.
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Old 01-15-2021, 05:29 PM
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I went through this exact swap a few years ago on my 272. I used Edelbrock Performer RPM Air Gap intakes with Quick Fuel 650 with manual secondary's. Your also going to have to change up your fuel system to bring the pressure down for the carbs. For simplicity I went to mechanical pumps mounted on the engine. just take off the block off plates and you should be good to go that route if you choose.

Good luck on the swap. The EFI was cool but without a way to troubleshoot issues and no longer being able to get parts for them it was an easy decision.
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