Which heads should i use?
Thread Starter
Member
Joined: Mar 2003
Posts: 395
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From: HOULKA MISSISSIPPI
Car: 1989 pontiac firebird formula
Engine: Currently building a 355
Transmission: 700r4
Which heads should i use?
O.K. heres the deal my father in law has a salvage yards so I can get any of these heads for free. The question is i have a 305 l03 right now with the swirlport heads and I am wanting to do a cam swap and i heard that these heads will hold back any cam upgrade from reaching its full potential and im wanting to get rid of them the imformation im about to post is off of www.mortec.com i have three sets to choose from ,
1st set 3973487....71-72...350..........used on 71-72 350 LT1, 75cc chamber
2nd set 14102193...87-up...305/350......1.94"/1.5" valves
3rd set 3774682....60-64...283/327......70cc chambers
I wanna be able to rebuild the heads upgrade the valves and port them and use them on a 355 that im going to build at the first of next year for it I'm just going for a better power range out of the l03 that i have right now until i get the money for the 355.
please give me your thoughts on these heads i know there are a plethra of aftermarket heads out there but dont have the money to put into a set right now. any and all replys welcome.
thomas
p.s. sorry for the long post.
1st set 3973487....71-72...350..........used on 71-72 350 LT1, 75cc chamber
2nd set 14102193...87-up...305/350......1.94"/1.5" valves
3rd set 3774682....60-64...283/327......70cc chambers
I wanna be able to rebuild the heads upgrade the valves and port them and use them on a 355 that im going to build at the first of next year for it I'm just going for a better power range out of the l03 that i have right now until i get the money for the 355.
please give me your thoughts on these heads i know there are a plethra of aftermarket heads out there but dont have the money to put into a set right now. any and all replys welcome.
thomas
p.s. sorry for the long post.
Supreme Member
Joined: Jul 1999
Posts: 18,457
Likes: 16
From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
They aren't any of them any good for your situation.
The 193s are swirl-port 350 heads; same crap as what you've got, except bigger valves and lower compression. The 283 heads won't fit your motor because they don't have the bolt holes on the ends for your accessories to bolt to, and are low-perf heads besides. The 487s flow good but have huge chambers, so you'd end up with less than 8:1 compression on your 305.
All in all, a poor selection.
Go to the junkyard and get a set of 416s off of a early-mid 80s Caprice 305 or something.Or, if you're lucky and he has a TPI 305 car in there from 87 up, get the heads off of that. Either of those would be vastly better than any of those others. Port them, have larger valves in them, and you can use them on a 305 now and a 350 later.
The 193s are swirl-port 350 heads; same crap as what you've got, except bigger valves and lower compression. The 283 heads won't fit your motor because they don't have the bolt holes on the ends for your accessories to bolt to, and are low-perf heads besides. The 487s flow good but have huge chambers, so you'd end up with less than 8:1 compression on your 305.
All in all, a poor selection.
Go to the junkyard and get a set of 416s off of a early-mid 80s Caprice 305 or something.Or, if you're lucky and he has a TPI 305 car in there from 87 up, get the heads off of that. Either of those would be vastly better than any of those others. Port them, have larger valves in them, and you can use them on a 305 now and a 350 later.
Joined: Mar 2000
Posts: 43,187
Likes: 43
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Now apologize for posting on two forums and not disclosing that...
(Basically same answer given on Swap forum)
(Basically same answer given on Swap forum)
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