XFI 268 on stock 350??
11-01-2016, 08:44 PM
#1
XFI 268 on stock 350??
So I was gonna do a 383 build but I scrapped it and bought a new truck instead.. So I just wanna cam swap my current 350 and looking for options.
Its a 350 goodwrench motor with a HSR on it LT headers and 2500 converter.. Its pretty fun, I have a small crane cam in it now. So I'd like to add at least the 268 to it with out much other work. I don't drive it much either. Oh and I bought a 05 Ram srt-10 so I just didn't buy a boring truck with motor money lol..
Its a 350 goodwrench motor with a HSR on it LT headers and 2500 converter.. Its pretty fun, I have a small crane cam in it now. So I'd like to add at least the 268 to it with out much other work. I don't drive it much either. Oh and I bought a 05 Ram srt-10 so I just didn't buy a boring truck with motor money lol..
11-11-2016, 11:48 AM
#2
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Re: XFI 268 on stock 350??
I had a Comp 212/218 HR in my 350 with HSR. Good combo with TPI and since I had an 89 with MAF it didn't need tuning. When I went to the HSR it needed tuning. The cam idled very well and didn't lope much at all.
But you have an 85 which I presume is still speed density. With the HSR it will need tuning so you should be able to cam it too. I think the 268XFI would be a good cam even for a stock motor with the HSR. I think the 218/224 XFI would lope a little with a 350. If you can't tune it and have speed density ecm I wouldn't go with the HSR and you need to be careful with how much cam (overlap really) you try to use.
But you have an 85 which I presume is still speed density. With the HSR it will need tuning so you should be able to cam it too. I think the 268XFI would be a good cam even for a stock motor with the HSR. I think the 218/224 XFI would lope a little with a 350. If you can't tune it and have speed density ecm I wouldn't go with the HSR and you need to be careful with how much cam (overlap really) you try to use.
11-17-2016, 07:19 AM
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Re: XFI 268 on stock 350??
You're probably right. I think 3rd gens went SD in 90. I may be getting confused with the Mustangs. I think they went to MAF as the Camaros were going to SD.
Bottom line is MAF is more adaptable to cam changes since it measures (sort of anyway) air flow. Still, the HSR changes AE requirements so there may be tuning requirements when the two are combined. A cam only change would likely be tolerated with TPI & MAF. XFI 268 should be a good cam for a 350.
Bottom line is MAF is more adaptable to cam changes since it measures (sort of anyway) air flow. Still, the HSR changes AE requirements so there may be tuning requirements when the two are combined. A cam only change would likely be tolerated with TPI & MAF. XFI 268 should be a good cam for a 350.
11-17-2016, 12:19 PM
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Re: XFI 268 on stock 350??
A 268XFI won't fit with stock heads, not enough retainer to seal clearance.
Max lift .460
Max lift .460
11-17-2016, 12:39 PM
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Re: XFI 268 on stock 350??
I had an XFI280 in a pretty stock 355 bottom end with vortec heads modded for the lift. Worked great, so I do not see why the XFI268 wouldn't work well. I'm also still running a MAF
11-17-2016, 01:33 PM
#7
Re: XFI 268 on stock 350??
85 ecm sucks. You are better off goin to 86-89 maf sensor and ecm. Need repin the harness some
268 on a 350 is awesome but need the heads modded to handle the lift. Also recommend ls7 lifters and atleast beehive springs or a double with 140-150 lbs seat pressure 375-400 open
268 on a 350 is awesome but need the heads modded to handle the lift. Also recommend ls7 lifters and atleast beehive springs or a double with 140-150 lbs seat pressure 375-400 open
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01-12-2017, 12:34 PM
#8
Re: XFI 268 on stock 350??
85 ecm sucks. You are better off goin to 86-89 maf sensor and ecm. Need repin the harness some
268 on a 350 is awesome but need the heads modded to handle the lift. Also recommend ls7 lifters and atleast beehive springs or a double with 140-150 lbs seat pressure 375-400 open
268 on a 350 is awesome but need the heads modded to handle the lift. Also recommend ls7 lifters and atleast beehive springs or a double with 140-150 lbs seat pressure 375-400 open
What would be the largest cam that you would recommend for stock unmodified heads? Or would sotck corvette heads accommodate the 268? with better springs?
BTW I have the commander 950 ECM so tuning isnt an issue.
I filled out the comp cam request form and got recommended the entire xfi280 kit. Which wouldnt work with my heads. I would be pissed if I bought it.
01-26-2017, 12:11 PM
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Re: XFI 268 on stock 350??
280 too big for low compression motor you wont like it
Run some spring pressure with those lobes like Orr said hoping its roller those on FT go flat fast waste of $ imo.
if anyones guilty of overcamming its me lol
The rumpity rump thing is overrated in some cases
Get add a better head it will really wake up
Issue is buying used dont know what youre getting sometimes the seller may not be aware of what they need to boot.
Run some spring pressure with those lobes like Orr said hoping its roller those on FT go flat fast waste of $ imo.
if anyones guilty of overcamming its me lol
The rumpity rump thing is overrated in some cases
Get add a better head it will really wake up
Issue is buying used dont know what youre getting sometimes the seller may not be aware of what they need to boot.