I recently picked up a 71 Mav 2dr to use as a parts car for my 76 2dr project. Mostly for the bumpers and valances. The vin decoder says it came with a 200 i6 with an automatic transmission. but when I ran the casting code on the motor thats in it, it came back as a 1981 block. Wikipedia calls this a Big Bell 200, and also says it is sought after because it can be modified to accept a Ford small block V8 six bolt bell housing. My question is why is this an advantage? And would this 200 be a better performance build candidate for my 76 Maverick than the 250 that is in it now.
i never knew the 200 ever came with the v8/250 bellhousing it just means the bellhousing will mount to a ford small block v8 so if you ever wanted a swap in a v8 or 250 to the bellhousing/tranny it would be a direct fit. the motor other than the mounting slots should be the same. performance candidate? i would swap the head off the 200 and put it on the 250. the late model heads (if the 200 is a 81' model) have much higher flow rates. mill the head down to bring up the motors compression and mount it to the 250, would give it some more bang. i would check fordsix.com , classininlines.com , or check out the ford six performance handbook for more details on the bellousing mounts/head swap though the above was my rambling and my
1980-85, 200's were the "big bell" ones. Not a direct swap without drilling. On the 302 bellhousing, you need to redrill the top 2 holes of the V8 bellhousing to fit on the narrower 200 block. The big bell 200 bellhousing is therefore, too narrow on the top 2 holes to fit the 302. Not sure if that can be redrilled, but the top 2 holes are for sure different. There are pictures at Ford Six if anyone is interested. http://fordsix.com/V8Bell.php I guess the advantage that stands out to me, is you can easily modify the 302 bellhousing and add a modern automatic like an AOD or the T5 manual, and gain the advantage of overdrive.
Wait a minute. I'm trying to catch up here. Does this mean that my 1974 250 has a V8 bell plate and can accept a newer transmission? I'm confused.
As far a bolt pattern to the engine block, 250 and 302 have the same bellhousing. Different transmissions (T5 for example) have a unique bellhousing, but will bolt up to the older 302 and 250 pattern.
81 200 I6 head/Intake specs You've pretty much answered my next question, which was is the 81 200 head a better choice than my 76 250 head. I thought so but I cant seem to find the general specs for the 81-83 200. Classic Inlines doesn't show the info on these years, just specs for up to 1980. I think I'll take the 200 head to my machinist in the morning to see if he can mill and hog out the intake log for a 2 barrel adapter. I guess while I've got him working on it I'll have him do a valve job to. The Parts car came with a really good looking exhaust system. It's still sporting the stock manifold, but someone built a custom 2 inch pipe out to a strait through muffler and then split to duals out the back. I think I can get her breathing pretty well for not allot of money. Thanks allot for the info.
upon reading it seems the 77 and later heads have hardened valve seats and 1420cc intake manifold volume reading it seems the 76 either has 1240 (flat top intake) or 1345 (hex shaped intake) either way, yes go with the later head. yea decking or milling .035 -.040 should get you in the appropriate compression if you go with a felpro head gasket.
Thanks allot. I cant wait to see what kind of power increase I can get out of the old 250. She runs pretty well as it is, but I'd be tickled with another 15 or 20 HP. I still cant believe how lucky I was to find this 71 parts car so cheap. I bought the car just for the small bumpers and valances, but the Low starter 200 is a real nice bonus.
