OPINION OF THE COURT

JAMES ROSEN, Circuit Judge.

On July 30, 1964, at 3:30 A.M. appellee Paul J. Glick, an over-the-road truck operator, was involved in a highway accident with an automobile on Highway 230 by-pass near Lancaster, Pennsylvania. Glick suffered substantial injuries resulting in total and permanent paralysis from the waist downward, and was hospitalized from the date of the accident until February 12, 1965.

The complaint was filed in the United States District Court for the Eastern District of Michigan on August 26, 1965. An order was entered on May 18, 1966 transferring this action to the United States District Court for the Eastern District of Pennsylvania. On October 5, 1966 Rockwell-Standard Corp. was joined as third-party defendant. The trial resulted in a verdict on November 11, 1969 for Glick and against White, in the sum of $307,400, and in favor of White against Rockwell for the full amount of the jury's award to the plaintiff.

Motions for judgment N.O.V. and new trial were made by White and Rockwell and denied. On December 16, 1969, plaintiff filed a motion under F.R.Civ.P. 59(e) requesting the court to amend the judgment to include interest at the rate of 5% per annum from the date of the institution of the suit pursuant to a Michigan statute. On October 23, 1970, the court entered final judgment, amending the judgment of November 11, 1969 to include pre-judgment interest in the amount of $64,659.52. Glick's earlier motion to assess counsel fees as part of the judgment against White was denied, D.C., 317 F. Supp. 42.

Notice of appeal was filed by White on October 26, 1970. Rockwell entered into an agreement with White which resulted in the complete indemnification of White, compromise and settlement of all counsel fees and expenses due White from Rockwell, and the assumption by Rockwell of the entire prosecution of this appeal for and in the name of White. In addition, White was given a complete hold harmless agreement against any judgment arising out of this case.

The theory of plaintiff's suit was based on an alleged defect in a truck spring manufactured by Rockwell and installed by White in the truck driven by Glick. After the accident, it was discovered that the right front spring on the truck which joins the suspension system to the truck body had broken at the spring "eye" — the place where the spring is curled to receive a rod or bushing from the cab to make the joint between truck spring and truck body. Abundant expert testimony was introduced to determine whether the spring eye was broken as a result of fatigue failure due to certain gouge marks allegedly impressed on it during manufacture, or whether the break was caused by the force of the collision. The testimony of Mr. Louis J. Jelsch, chief suspension engineer for Rockwell, stated the conclusion that had the spring broken on the highway, prior to the collision, the truck would have veered out of control to the right.

The threshold issue on appeal is whether Rockwell is estopped from disputing the authenticity of certain sections of trial exhibits cut from the Rockwell spring which White accepted as genuine. At trial, Rockwell questioned the authentication and tracing of these items and asked the trial judge to exclude any testimony based on these exhibits. The trial judge allowed the exhibits and the testimony related to it and overruled Rockwell's objections.

Appellant White took the position at all relevant times that the exhibits were genuine. In his closing argument counsel for White expressly requested the jury to find that the spring as manufactured by Rockwell, sold to White and mounted on the right front of the Glick truck was defective because of the tool or gouge marks impressed into the steel at the time of manufacture.

It has been held that judicial admissions are binding for the purpose of the case in which the admissions are made including appeals, State Farm Mutual Auto Ins. Co. v. Worthington, 405 F.2d 683 (8th Cir. 1968), and that an admission of counsel during the course of trial is binding on his client. Rhoades, Inc. v. United Air Lines, Inc., 340 F.2d 481 (3d Cir. 1965). However, to be binding, judicial admissions must be unequivocal. Oscanyan v. Arms Co., 103 U.S. 261, 26 L.Ed. 539 (1880), The Doyle, 105 F.2d 113 (3d Cir. 1939), Rhoades, Inc. v. United Air Lines, Inc., supra. The scope of judicial admissions is restricted to matters of fact which otherwise would require evidentiary proof, and does not include counsel's statement of his conception of the legal theory of a case. New Amsterdam Casualty Co. v. Waller, 323 F.2d 20 (4th Cir. 1963), cert. denied, 376 U.S. 963, 84 S.Ct. 1124, 11 L.Ed.2d 981 (1964).

The application of the above principles compels the conclusion that the plain and unequivocal acceptance at trial of the authenticity of the spring exhibits constitutes a binding admission by White. Rockwell argues, however, that an exception should be made to the usual preclusion cases involving a single party in order that it [Rockwell] may be afforded complete defense protection under F.R.Civ.P. 14.

Rockwell oversimplifies the issue. We are not confronted merely with the failure of White to raise points at the trial level. White took a definite position on the authentication of the truck spring sections, and benefited from its conduct by the jury's plain finding that the truck spring was rendered defective by the tool or gouge marks.

In Scarano v. Central R. Co. of New Jersey, 203 F.2d 510 (3d Cir. 1953), Judge Hastie carefully drew a rule of "estoppel" on the circumscribed canvass of the "particular facts and circumstances" of each case:

"The rule we apply here need be and is no broader than this: A plaintiff who has obtained relief from an adversary by asserting and offering proof to support one position may not be heard later in the same court to contradict himself in an effort to establish against the same adversary a second claim inconsistent with his earlier contention. Such use of inconsistent positions would most flagrantly exemplify that playing `fast and loose with the courts' which has been emphasized as an evil the courts should not tolerate."

Cf. Colonial Refrigerated Transportation, Inc. v. Mitchell, 403 F.2d 541 (5th Cir. 1968).

Appellant argues that the preclusion rule is not applicable to the factual situation here, relying upon the decision of this court in Humble Oil and Refining Co. v. Philadelphia Ship Main Co., 444 F.2d 727 (3d Cir. 1971). Humble Oil dealt primarily with the applicability of the "vouching-in" process whereby a shipowner's tender of defense in a longshoreman's suit was sought to be used as a basis for liability against a stevedore in a later indemnification suit. A longshoreman brought suit against a shipowner for injuries sustained in the course of his employment. The shipowner tendered defense of the action to the stevedore. The latter refused to accept the tender. He was not impleaded in the original action. Judgment was recovered against the shipowner who instituted an action in admiralty against the stevedore seeking indemnification for the damages awarded in the original action. The district court granted summary judgment to the shipowner predicated on the determination that the seven special interrogatories posed to the jury in the original action resolved all general issues of material fact, and that the stevedore was collaterally estopped from litigating those facts. We reversed, refusing to bind the stevedore to an election not to defend, where the facts at the time of the tender of defense did not demonstrate `"that liability [would] eventually fall upon the indemnitor," thereby placing him under a duty to defend.'

Rockwell's reliance on Humble Oil is misplaced. The implication of Humble Oil is that, had the stevedore been impleaded, it would have been given sufficient notice of its potential liability, and its continued failure to enter a defense would have made the findings of fact binding on it for the purpose of indemnification. The court's concern was with the marginal notice provided by the "vouching-in" process, and the unfairness of using it as a basis for applying the principle of collateral estoppel in a subsequent suit.

No such concern is warranted in this case. Rockwell deliberately elected to prosecute the appeal in White's name. The fact that White's judgment against Rockwell was recovered in the same suit which resulted in favor of appellee, Glick, does not make Scarano inapplicable. Rockwell argues that, even had it chosen to appeal from the judgment recovered by White, it would still have been bound by the principal verdict. Rockwell had the right to raise objections to the evidence at trial — and did so. It had the right to file all trial and post-trial motions and did so. And Rockwell had the right and opportunity to preserve its own trial position by taking an appeal from the judgment which was rendered against it, in favor of White. As to that judgment Rockwell would have had to answer only for its own conduct and its own admissions. We find the statement of appellee on this issue to be well taken:

"But now having assumed White's party and judgment identity so as to completely protect White, Rockwell bridles at the record White made at trial. Thus, Rockwell's `dilemma' on this appeal results from no impairment of its `complete defense protection.' It results from a conscious and deliberate choice Rockwell made after judgment to protect the White Motor Company, come what might. But in doing this, it cannot wash the record so as to nullify the effects of White's trial conduct and admissions. These remain in the record, * * *, regardless of who prosecutes the appeal in White's name."

In short, Rockwell chose to stand in the shoes of the principal defendant, White. It's right on appeal can be no greater than those of White. It aligned itself with White against Glick with the proverbial axe aimed at the plaintiff's judgment against the primary defendant [White]. It cannot now be heard to complain that it made a bad alliance.

We conclude that the rule of Scarano operates to bar the appellant from raising the issue of authenticity on this appeal.

Appellant challenges the action of the trial court in amending the judgment to include pre-judgment interest.

It does not dispute the trial court's reliance on the Michigan conflict of law rules. It argues rather that the court erroneously applied those rules in allowing pre-judgment interest under the Michigan statute, for the benefit of a Pennsylvania resident suing upon a Pennsylvania tort cause of action.

We find the district court's award of pre-judgment interest to be proper. Resort to the conflict laws of Michigan was correct. Neville Chemical Co. v. Union Carbide Corp., 422 F.2d 1205 (3d Cir. 1970); cert. denied 400 U.S. 826, 91 S.Ct. 51, 27 L.Ed.2d 55 (1970). Lynch v. Electro Refractories and Abrasives Corp., 408 F.2d 363 (6th Cir. 1969). The trial judge was entrusted with the function of applying the decisional law of Michigan defining the scope and effect of the pre-judgment interest statute. His determination comports with the holdings of the Michigan courts. Ballog v. Knight Newspapers Co., 381 Mich. 527, 164 N.W.2d 19 (1969); Cosby v. Pool, 194 N.W.2d 142 (Court of Appeals, Mich. 1971), leave to appeal to Michigan Sup.Ct. denied 1/13/72; Swarthout v. Beard, 190 N.W.2d 373, 380 (Court of Appeals of Mich. 1971).

Error is alleged in the district court's entertainment of appellee's motion, which was originally filed under F.R.C.P. 59(e), as a Rule 60(a) motion. This rule provides that clerical mistakes in a judgment may be corrected at any time. The court held that, since the Michigan pre-judgment interest statute requires the allowance of interest from the date of filing suit as a matter of right, the omission of pre-judgment interest was a "clerical mistake" which could be corrected by motion under Rule 60(a). We agree. The addition of prejudgment interest under the Michigan statute is merely a ministerial act which cannot be denied through mere inadvertence, regardless of whether the error goes undiscovered for a period exceeding ten days. See In re Merry Queen Transfer Corp., 266 F. Supp. 605 (E.D.N.Y.); Gilroy v. Erie-Lackawanna Railroad Co., 44 F.R.D. 3 (S.D.N.Y. 1968). Cf. Colonial Refrigerated Transportation, Inc. v. Mitchell, 403 F.2d 541 (5th Cir. 1968), where the court dealt with the issue of pre-judgment interest as damages.

Finally, we summarily dispose of appellant's remaining assignments of error going to the trial court's ruling on cross-examination of plaintiff regarding two written statements and third party defendant's attempt to prove the manner of failure of another steel spring. The two statements were taken from Glick by insurance investigators while Glick was hospitalized in the intensive care unit under heavy sedation. Glick testified that he remembered absolutely nothing about the statements, but that the signature did look like his. The court refused to allow these statements to be used to impeach Glick on cross-examination until they were sufficiently authenticated. Appellant was given the right to recall Glick for cross-examination after authentication by the scriveners. Rockwell called two insurance investigators as witnesses and both statements were read to the jury. However, Glick was never recalled and confronted with these statements. The record indicates that the jury was adequately instructed on the weight and consideration to be given the statements. We perceive no harmful or prejudicial error in the trial judge's rulings.

Evidence was proffered by defendant regarding another spring eye which was shown to appellee's expert witness, Henry Fuchs. The record reveals a serious disagreement as to whether Mr. Fuchs did in fact identify the condition of this trial exhibit. Appellant contended that Mr. Fuchs had described the break in the spring eye as having been caused by fatigue failure, and attempted to introduce evidence to show that the test sample failed by the application of one massive test load. The court excluded this evidence as collateral and because a proper foundation had not been laid.

Experimental evidence is admissible so long as it is relevant and probative, and such evidence has probative value if the conditions of the experiment are identical with or similar to the conditions of the transactions in litigation. Crown Cork and Seal Co. v. Morton Pharmaceuticals, Inc., 417 F.2d 921 (6th Cir. 1969). A ruling on the admission or exclusion of experimental evidence in a particular case rests largely in the discretion of the trial judge and his decision must not be overturned on appeal absent a clear showing of an abuse of discretion. Ramseyer v. General Motors Corp., 417 F.2d 859 (8th Cir. 1969); Hopkins v. E.I. Dupont De Nemours Co., 199 F.2d 930 (3d Cir. 1953). The record indicates that the trial judge exercised sound discretion in refusing to admit the proffered experimental evidence.

The judgment of the district court will be affirmed.