hey, i was reading at tccoa that if you had an auto tranny t-bird, and you were thinking of upgrading to the cobra dohc engine, you'd have to go through this big frankenstein operation with the eec and the wireing harness because of the cobra motor not ever being equipt with an auto tranny. (read about it at http://www.tccoa.com in the tech article "engines".) well, what if you just bolt in a "mk vii" engine? it's the same motor as the cobra (mostly) and the mk vii had auto trannys (i think only auto). so, what do you think? is that an easy swap? the reason i ask, this site http://www.shoclub.com has the mk vii engine for $2295!!!! thats a 90 hp increase over our stock motor, and if you think about it, more cost efficient than getting new heads and maf and tb, etc. tell me the good, the bad and the ugly guys. cause if it's a simple swap, i'm saving for this all the way.

The Mark VIII engine swap isn't a bad idea, but while easier than installing a Cobra engine, it's still considerably more difficult than installing a 99+ mustang 4.6L. You still need a new eec and wiring harness for the DOHC and the intake manifold won't fit under your hood. You would have to get an aftermarket cowl induction hood which would run you another $750-$1000 for the hood, prep-work, paint, and installation. When you consider that if you shop around you can find a low mileage PI 4.6 SOHC complete engine for under $1500, the money you save is a good start toward a forced induction setup. Remember also that the stock Mark VIII only ran low 15 second quarter mile times. The thunderbird has slightly quicker times with that engine. A PI 4.6 in a thunderbird will get you low to mid 14 second quarter mile times. On the other hand, the DOHC will probably have more room to grow. There's nothing wrong with swapping in a Mark VIII engine but, IMHO, the PI 4.6 is the better option here. Hope this helps... Kenny

[The Mark VIII engine swap isn't a bad idea, but while easier than installing a Cobra engine] This is a good point but.... [it's still considerably more difficult than installing a 99+ mustang 4.6L. You still need a new eec and wiring harness for the DOHC and the intake manifold won't fit under your hood.] Not realy the mark viii 4.6L 4V is a direct swap with no i repeat no hood modifications as long as you use the factory mark viii intake tubing very restrictive but will clear. You are thinking about the 5.4 swap. you will need a 4-5" cowl hood to clear that intake. yes you will need a new wiring harness but only the underhood one the eec will require a chip reburn or a mark viii chip but it is the same eec all fords have. [You would have to get an aftermarket cowl induction > hood which would run you another $750-$1000 for the hood, prep- work, paint, and installation.] no you won't but they look cool.... [When you consider that if you shop around you can find a low mileage PI 4.6 SOHC complete engine for under $1500,] good luck after crating and shipping costs you are looking at more like $2200 if you cant find one in your state. [the money you save is a good start toward a forced induction setup.] junkyard markviii engine, all neccesary harnesses and transmission included $2500. with this you get the higher stall converter you will need and a fresher tranny same as t-bird but flex plate is different and torque converter is better. [Remember also that the stock Mark VIII only ran low 15 second quarter mile times.] try mid 15's 15.4-15.6 @96mph [The thunderbird has slightly quicker times with that engine.] a tenth or so due to a weight difference of 150lbs= 15.3-15.4 et [A PI 4.6 in a thunderbird will get you low to mid 14 second quarter mile times.] i am sorry but what kind of crack are you on a "pi" mustang runs 14.6- 14.8 in an auto and 14.2-14.5 in manual and that car is almos 500lbs lighter you are best to see a mid-low 15. High 14 like 14.99 with a five angel valve job befor you do the swap low 14 sec slip you will need a superchareger or some juice. [On the other hand, the DOHC will probably have more room to grow.] add a supercharger 8-10lbs of boost, 3:73's and a true dual exaust to a bone stock mark viii and you will be seeing ultra low 14's to high 13's There's nothing wrong with swapping in a Mark VIII engine but, IMHO, the PI 4.6 is the better option here. ok lets break it down pi heads five angle valve job trying to perfectley time two cams in the confines of a t-bird engine bay 1)heads used $700 new $1000 2) new intake because a 94-95 intake won't work used $250 new $400 3) all necessary new plumbing top mate up to the new intake $75 4) time and labor if you don't do it yourself you don't want to know. this is just for a head swap using your existing engine. add about $1500 for a new motor because the "pi" motors are scarce and run about $2000 you can get a 97-98 4.6 for $1500 but it is the same motor as you car has now 99-00 is the only years you can use because the 01-03 have returnless fuel systems and you do not want to go there. power increase 45-50hp you will not get the 260hp rating mustangs have due to the pathetic headers intake and exaust the t-bird was fitted with a true dual set up with "x"pipe will get you near that number. mark viii set up complete set up because j-yards average ones anyway don't realize the potential a lincoln had so they are cheaper than "mustang" engines and the continental also had the 4v so that is something to look for also $2500 including all harnesses and transmision. pull the motor and drop in new 4v 2 days with some buddies and beers priceless. figuring out new harness is simple you will have just have to unplug it from the firewall of the mark viii and plug it back into the t- bird matching plug on the firewall. the eec of the t-bird is the same but getting the mark viii is reccomemded due to t

i'm still thinking economical though. the stock mk vii engine gets 290 hp, and can get up to 335 with small mods. add a 100 shot of nos via nx kit, and i'll be running a very fast car for not too much cash. i haven't found any good deals on the pi engine yet, and the bullit engine (4.6 sohc 270 hp) still costs $1000 more than the mk vii engine. go figuire?!?!?!?!? i am trying to find the best way to 400 + hp without spending more than i should. the dohc mk vii seems to be a good way at the deal they are offering.

first off nos is a better kit with the direct port injection it is more expensive but better mixture for a better burn. cost effectiveness if that is you plan 400hp is an unrealistic number no offense. The best mark viii engine was 280hp in 94-98 with a shot of nos (and no it is not said "NOS" like the fast and the furious the stupid ricers. NOS is a brand name for "nitrous oxide systems") it is manufactured by edlebrock or hurst. anyway that just urks me thats all. NX systems are good too just get a bottle warmer with the kit. 400 hp is very obtainable with the mark viii engine but with a newer "cobra" intake instead of the mark viii intake will give you the 300 base hp rating you want. Get a set of agreessive bump sticks(cams) from sean hyland motorsports. If you are going to go nitrous they tend to prolong the intake duration and lift without overlap into the exaust lobe so you nitrous has a good volume of air to work with. Without running out the exaust port. Some valve work with larger intake and exasust work and some titanium retainers and better valve springs will be needed if you want to hold that 400+hp for any duration of time expecially if you are planning on high revving 1/4 mile runs. otherwise you may lift a valve not good, if you are runnnig nos make sure you upgrade your oil pump, fuel pump and add a windage tray to the bottom end luckilly the cobra mill comes with a main girdle to tie things together but the mark viii may not so that is a definite upgrade while the motor is out. I could go on for hours if you have any specific questions just ask. LAter