250/t5 maverick

[maverickhead]

Hey 6 folks,I know I've brought this up in an old post,but still got some ??.Any estimates and/or suggestions are greatly appreciated.Here's what I'm thinking;
'74 250 w/'77-up head(how much milling?)
255 v8 pistons(are they a direct bolt in,any mods required?)
header & 2 1/2" single system
holley 2bbl
duraspark
what cam??
3.55-3.80 gears
t-5 trans
Going to be a driver,'70 Maverick 2dr,should weigh less than 3,000 w/ driver.My goal is to acheive(before I even start,is it feasible??)22-26mpg and run 9.90 1/8 //high 15 sec 1/4.

 

[Anonymous]

The 255 pistons are a great way to bump the CR a bit, and gain a tighter quench area. The 250 had a huge deck height to keep the compression ratio down. I'd mill the head just enough to get it true. Try to shoot for 58-60 cc chambers depending on what your final deck height will be. Will you be decking the block any?

Here's a great compression calculator for all that:
http://falconperformance.sundog.net/compcalculator.asp

Bolt a Holley 500 directly to the log, do some pocket porting, a 3 angle valve job, and go with a cam in the 220* @ .050" range with about .500" lift, and you should be driving deep into the 15s soon.

 

[maverickhead]

And the 255 pistons will work on the stock rods?Only going to mill what I have to,planned on cutting the head anyway,you know for trueness & all.

 

[STEVEN.]

I've got an old set of Maverick brake/clutch pedals & a console. I've alaway's wondered about the T-5 swap,since I already have all the parts(including the Tranny Hump section...). I'll just add this swap to the file cabinet under: "Someday." OO6./The-X-Or-Six!

 

[Anonymous]

And the 255 pistons will work on the stock rods?

Yep. The pin diameter is the same .9122" The only difference is the compression height is .05" taller.

 

[maverickhead]

That's good.Are they for the standard bore,or does it need bored to accept the v8 piston?

 

[Anonymous]

You don't have to overbore - same size.

 

[maverickhead]

Checked on 255 pistons-$26 each!Think I'll just deck the block as much as possible & cut the head a bit.BTW,looking at all my stuff,pretty sure I've got a '79 200 in an old '76 mav parts car,'79 head's good,huh?Also has the duraspark too.

 

[powerband]

To convert a 250 Auto to standard, you would need a SBF bell - correct?. Also the flywheel would not work from the SBF's because the flywheel for the six must be regular balanced not the 28oz or 52(?)oz imbalance - correct?.

Doesn't the 300 six also share the same bell? , how about the flywheel?

I was given a 250 without a flywheel or bell from a 'Stang six to eight swap but I haven't had much luck finding a flywheel for it (was C4). the SBF bell's seem pretty common but I am not sure if all the SBF's bells would fit. I know they switched to cable clutch setup in early 80's(?). I've been looking for a 250/Std shift Stang/Maverick flywheel and bell, but no luck so far.

Most junkyard's excuse me - recycling yards in N.E. are limited to recent wrecks and little else. Unless it's a late model Nissan, Dodge minivan or Saturn, they don't bother.

 

[Anonymous]

What I did was use a 10-/12" flywheel from a 289, and had my machinist remove the weight and balance it to zero. Then I used an aluminum 5.0L bellhousing. Equally, I could have used the 5.0L flywheel (both 10-1/2"). And remember, your bellhousing has to match your flywheel. You can't use a bell from a 300 (11") with a 10-1/2" flywheel.

You will be hard pressed to find a 10-1/2" flywheel with no counterweight. The 300 sounds like a good candidate, but they used an 11" flywheel/clutch in trucks. You'd have to use the big, heavy (iron), 11" bellhousing. A 240 or 250 from a car with a M/T application might be the ticket, if such an animal ever existed. Seems like they all had C4s behind them.

 

[Anonymous]

Checked on 255 pistons-$26 each!

I picked mine up from the 'zone for $12 a pop 3-4 yrs ago. They were branded "Badger" IIRC.

 

[MustangSix]

Just did a quick search of Evil-bay and found that Norther Auto parts has them for $74.99 a set.

http://cgi.ebay.com/ebaymotors/ws/eBayI ... eName=WD1V Even if you toss out the two extra, that's still only $12.50 each.

 

[maverickhead]

Well that makes me feel a bit better on the 255 piston prices.When doing the t5 swap(the car's a c4 originally)couldn't I just get everything off a 5 liter mustang from the flywheel back?Already have a friend who's done the cable clutch deal in his maverick(302 w/SROD 4spd)and I have a manual car here to rob from(pedals)

 

[Anonymous]

I recently got some Badger pistons from a gentleman on e-Bay.
Theyw ere the 255 pistons .030 OS.
Cost was $60 for the six.
This is the seller.
http://search.ebay.com/_W0QQfrppZ50QQfs ... ZjQ2asQ2as
He has a set of standard 200/250 Forged pistons right now on auction.($79)
http://cgi.ebay.com/ebaymotors/ws/eBayI ... ename=WDVW
Has a speed shop I think, not sure.
Do know he was very nice and worked with me on getting the pistons I wanted.
You may give him a try.
FWIW
DaveP kywoodwrkr

 

[Anonymous]

couldn't I just get everything off a 5 liter mustang from the flywheel back?

Yes, as long as you have the flywheel "zero balanced".