1992 lx 351w to 408 stroker problems

bsmi16490 · 07-26-2009, 09:13 PM

Good evening,

I purchased this car about 1 month ago. Here is the short list. 351w to 408 stroker, all forged, aluminum heads, aeromotive fuel system, 60lb injectors, tko600, d1sc procharger(9lbs). Car dynoed 598hp, 592 ft lbs back in march. To make a long story short a shop did some work on the car for the previous owner and knocked the tune out of the car causing it to run very rich. I knew it was rich and drove the car around a little and trashed the head gaskets. So here are my questions, whats the best head gasket for this application, how do i tell what thickness to purchase to ensure my CR does not change. Here is the jist of this car, if I cant make this combo more streetable than it is I am going to take it apart and sell everything and buy a new 347. This car has a very large cam thats causing it to "buck" at low RPM. It is very annoying right now and once the head gaskets and tuning are done hopefully it will take a little bit of the radical out of it. Let me know what yall think. Thanks

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MaroonNotchback · 07-26-2009, 09:33 PM

i say keep the 408 and the head gaskets don't really make a dramatic change in your cr but try and get the same thickness as your old head gaskets.

decipha · 07-27-2009, 09:45 AM

alright here it is take it or leave heres my insight

theres alot more to compression quench space than just CR, you want your quench area to be approx. .04 thick for max effeciency, so keep that in mind and measure your old gaskets.

cometic mls gaskets .04 thick compressed and get them .03 oversize larger than your bore which is probably 4.03 so get some 4.06s.

sell the cam you have now and throw in a nice little ford f303 cam it'll give you a nice idle and make decent power down low. 226 @ .05 288 adv 114lsa .320 lift on cam x 1.6 rockers will bring you to .512 lift which is perfect for a high hp street car, (x 1.7 rockers) will give you .544 lift which would be harsh on the streets but better for more track duty

Liquid_02 · 07-27-2009, 08:29 PM

When you have the gaskets out, measure them with a caliper (gaskets don't compress that much when they've been torqued), or if the number is still legible, look it up on the net. I just used factory 351 perma torque felpro gaskets on my 408

bsmi16490 · 07-28-2009, 10:53 PM

thanks guys, had the heads ches=cked today and they are within spec, no warping. Will put together with MLS cometic i think. So good luck to me.

P.S.I.cho · 08-06-2009, 11:38 PM

was gonna say run MLS fel-pros, btw dont run the f303 cam mentioned above, its not a bad cam but single pattern cams are old technology if your gonna go through the hassle of a cam swap get a custom or at least dual pattern positive displacement blower cam off the shelf from a reputable company.

kuikcat · 09-10-2009, 02:09 AM

sounds like a great build good luck

wagontrain · 09-12-2009, 02:40 PM

In my opinion you should use a Fel-pro 3933 performance gasket.It is cheaper to replace head gaskets than put a non desructable gasket in there and break a piston.Sort of a release valve.Unless you are racing it or deep pockets.

On the bucking part,pick a lower gear.

decipha · 09-28-2009, 07:16 AM

the mls gaskets are not by any means non destructable its the stock type gasket for 97+ ford v6 engines. The mls gaskets are much more forgiving than the old stock type gasket which are as you described 'old technology'

a single pattern or dual pattern cam isin't going to make a bit of a difference if your making the power you want where you want. A single pattern cam is 'old technology' but so is these blocks that were working with here. Theres absolutely nothing wrong with the f303 cam which has been known to perform very well on boosted applications. Another nice contender would be a cobra fox or 93 tbird cam, there both the same and people are having very good success with it.

wagontrain · 09-29-2009, 07:21 AM

Quote:

Originally Posted by decipha

the mls gaskets are not by any means non destructable its the stock type gasket for 97+ ford v6 engines. The mls gaskets are much more forgiving than the old stock type gasket which are as you described 'old technology'

a single pattern or dual pattern cam isin't going to make a bit of a difference if your making the power you want where you want. A single pattern cam is 'old technology' but so is these blocks that were working with here. Theres absolutely nothing wrong with the f303 cam which has been known to perform very well on boosted applications. Another nice contender would be a cobra fox or 93 tbird cam, there both the same and people are having very good success with it.

Old Technolgy is still Technolgy